Patent Publication Number: US-2022224665-A1

Title: Notification Message Preview Method and Electronic Device

Description:
This application claims priority to Chinese Patent Application No. 201910447164.1, filed with the China National Intellectual Property Administration on May 27, 2019, and entitled “NOTIFICATION MESSAGE PREVIEW METHOD AND ELECTRONIC DEVICE”, which is incorporated herein by reference in its entirety. 
     TECHNICAL FIELD 
     This application relates to the field of terminal technologies, and in particular, to a notification message preview method and an electronic device. 
     BACKGROUND 
     Currently, a notification panel (notification panel) is set on an electronic device such as a mobile phone, to display a notification message received by an operating system or an application. The mobile phone is used as an example. As shown in  FIG. 1( a ) , the mobile phone may display a status bar (status bar)  101  when displaying applications on a home screen. The status bar  101  may display time, a battery level, signal strength, a Bluetooth status, an operator name, and the like. 
     If the mobile phone detects that a user drops down the status bar  101 , as shown in  FIG. 1( b ) , the mobile phone may display a drop-down menu  102 . When a notification message of a system or an application exists in the mobile phone, the mobile phone may display the notification message in a notification panel  103  of the drop-down menu  102 . When there are a plurality of notification messages of a same application (for example, a Messages app), still as shown in  FIG. 1( b ) , the mobile phone may display the plurality of notification messages in a form of a message group  104  in the notification panel  103 . 
     Generally, the message group  104  has an expanded state and a collapsed state. As shown in  FIG. 1( b ) , the mobile phone may display the message group  104  in the collapsed state by default, to reduce display space occupied by the notification messages in the notification panel  103 . After detecting that the user taps the message group  104 , as shown in  FIG. 1( c ) , the mobile phone may display the message group  104  in the expanded state. In the expanded state, the mobile phone may display each notification message in the message group  104  in a form of a card in the notification panel  103 . 
     Because a spacing between adjacent cards is relatively large, when the message group  104  includes a large quantity of notification messages, the user needs to swipe up and down on the notification panel  103  to preview each notification message. In addition, w % ben the user wants to display the expanded message group  104  in the collapsed state, the user needs to return to the top (or the bottom) of the plurality of notification messages and tap a corresponding collapse button. Consequently, user experience in browsing and managing the message group  104  is poor. 
     SUMMARY 
     This application provides a notification message preview method and an electronic device, to provide a user with a function of quickly previewing a plurality of notification messages in a message group in a notification panel. This improves management efficiency and usage experience of the user on the message group. 
     To achieve the foregoing objective, the following technical solutions are used in this application. 
     According to a first aspect, this application provides a notification message preview method, including: An electronic device displays one notification message in a message group (the message group includes N notification messages, where N is an integer greater than 1) on a first card, where other notification messages in the message group are hidden. In this case, the message group is in a collapsed state. Further, the electronic device may receive a preset operation that is entered by a user to a first card. In this case, in response to the preset operation, the electronic device may display M notification messages (M is an integer less than or equal to N and greater than 1) in the message group on a second card, where the M notification messages are M of the N notification messages, and the M notification messages include the notification message that is displayed when the message group is in the collapsed state. In this case, the message group is in a preview state. 
     That is, when the message group is in the collapsed state, the electronic device displays only one notification message in the message group on the first card. When the user triggers switching of the message group from the collapsed state to the preview state, the electronic device may display a plurality of notification messages in the message group on one card (for example, the second card), where the plurality of notification messages include the notification message that is displayed when the message group is in the collapsed state. In this way, when viewing the message group in a notification panel, the user may switch the message group to the preview state and quickly preview the plurality of notification messages in the message group without expanding each notification message in the message group to view and manage each notification message. This improves management efficiency and usage experience of the user on the message group. 
     For example, in response to the preset operation entered by the user, the electronic device may display all the N notification messages in the message group on the second card, and in this case, M=N. 
     In a possible implementation, the preset operation may be a touch and hold operation. In other words, the user enters the touch and hold operation to the first card, to trigger the electronic device to switch the message group from the collapsed state to the preview state. 
     In a possible implementation, that the electronic device displays the M notification messages in the message group on the second card includes: The electronic device expands the first card to form the second card, and displays the M notification messages on the second card. In this case, an interface in which the first card is located is a same interface as an interface in which the second card is located. 
     Alternatively, that the electronic device displays the M notification messages in the message group on the second card includes: The electronic device displays the second card in an interface in which the first card is located, and displays the M notification messages on the second card. In this case, an interface in which the second card is located covers the interface in which the first card is located, and the first card does not disappear. 
     For example, when the interface in which the second card is located covers the interface in which the first card is located, the electronic device may further blur, mosaic, or hide the interface (namely, the interface in which the first card is located) covered by the second card, to prompt the user to focus on reading each notification message on the second card. 
     In a possible implementation, the second card includes a content summary of each of the M notification messages. Notification messages of chat messages are used as an example. A content summary of each notification message on the second card may include a name of a contact, a profile picture of a contact, message content, and the like that correspond to the notification message. 
     In a possible implementation, after the electronic device displays the M notification messages in the message group on the second card, the method further includes: The electronic device detects that a finger of the user leaves a touchscreen after the user performs the touch and hold operation; and the electronic device redisplays the one notification message in the message group on the first card, so that the message group returns to the collapsed state. 
     In other words, by using one touch and hold operation, the user may trigger the electronic device to switch the message group from the collapsed state to the preview state, and switch the message group from the preview state back to the collapsed state. This simplifies an operation process of switching the message group between the plurality of display states by the user. 
     In a possible implementation, after the electronic device displays the M notification messages in the message group on the second card, the method further includes: The electronic device detects that a finger of the user does not leave a touchscreen after the user performs the touch and hold operation, and detects that the user enters a first swipe operation to the second card. In this case, the electronic device may display the N notification messages in the message group on the second card in scrolling mode, so that the user can preview each notification message in the message group. 
     In a possible implementation, after the electronic device displays the M notification messages in the message group on the second card, the method further includes: The electronic device detects that a finger of the user does not leave a touchscreen after the user performs the touch and hold operation, and detects that the user continues to enter a second swipe operation to the second card. In this case, the electronic device may delete the second card and the M notification messages on the second card. That is, when the message group is in the preview state, the user can still delete all the notification messages in the message group by using the message group as a unit. 
     In a possible implementation, after the electronic device displays the M notification messages in the message group on the second card, the method further includes: The electronic device detects that a finger of the user does not leave a touchscreen after the user performs the touch and hold operation, and detects that the user continues to enter a third swipe operation to the second card. In this case, the electronic device may display a management button for the message group near the second card. The electronic device detects that the user selects the management button. Further, the electronic device may display a management menu, where the management menu includes one or more options of managing the message group, for example, an option of deleting the message group, an option of marking the message group as read, and an option of expanding the message group. That is, in the preview state, the user may manage, by using the management menu, a plurality of notification messages in the message group by using the message group as a unit. 
     In a possible implementation, after the electronic device displays the M notification messages in the message group on the second card, the method further includes: The electronic device detects that a finger of the user does not leave a touchscreen after the user performs the touch and hold operation, and detects that the user continues to enter a fourth swipe operation to the second card. In this case, the electronic device may display the N notification messages on N cards respectively, and the N cards are in a one-to-one correspondence with the N notification messages. In this case, the message group is in an expanded state. 
     It can be learned that, when the message group is in the collapsed state, by using the touch and hold operation, the user may trigger the electronic device to switch the message group from the collapsed state to the preview state. Further, the finger of the user does not need to leave the screen of the mobile phone, and may continue to enter a swipe operation to trigger the electronic device to switch the message group from the preview state to the expanded state. In this case, for the user, in an operation process from touching the screen to leaving the screen by the finger, the user may control the mobile phone to switch the message group between the three display states: the collapsed state, the preview state, and the expanded state. This simplifies an operation process of switching the message group between the plurality of display states by the user, and improves user experience. 
     In a possible implementation, detailed content of a corresponding notification message is displayed on each of the N cards. Notification messages of chat messages are used as an example. The detailed content may include receiving time, a name of a contact, a profile picture of a contact, message content, and the like that correspond to a corresponding notification message. 
     In a possible implementation, after the electronic device displays the N notification messages on the N cards respectively, the method further includes: The electronic device detects that the user enters a first swipe operation to a third card in the N cards, and further, the electronic device deletes the third card and a notification message on the third card. Alternatively, the electronic device detects that the user enters a second swipe operation to a third card in the N cards, and further, the electronic device displays, near the third card, a management button for a notification message on the third card. That is, in the expanded state, the user may manage each notification message in the message group by using a card as a unit. 
     In a possible implementation, after the electronic device displays a first notification message in the message group on the first card, the method further includes: The electronic device detects that the user enters the first swipe operation to the first card, and further, the electronic device deletes the first card and the message group. Alternatively, the electronic device deletes that the user enters the second swipe operation to the first card, and further, the electronic device displays the management button for the message group near the first card. That is, in the collapsed state, the user may manage the N notification messages in the message group by using the message group as a unit. 
     For example, the N notification messages in the message group may be notification messages from a same application. 
     According to a second aspect, this application provides an electronic device, including a touchscreen, one or more processors, one or more memories, and one or more computer programs. The processors are coupled to both the touchscreen and the memories. The one or more computer programs are stored in the memories. When the electronic device runs, the processor executes the one or more computer programs stored in the memories, so that the electronic device is enabled to perform the notification message preview method according to any one of the implementations of first aspect. 
     According to a third aspect, this application provides a chip system, where the chip system includes at least one processor and at least one interface circuit. The interface circuit is configured to read instructions stored in a memory, and send the instructions to the processor. When the instructions are executed by the processor, the electronic device is enabled to perform the notification message preview method according to any one of the implementations of the first aspect. 
     According to a fourth aspect, this application provides a computer storage medium, including computer instructions. When the computer instructions are run on an electronic device, the electronic device is enabled to perform the notification message preview method according to any one of the implementations of the first aspect. 
     According to a fifth aspect, this application provides a computer program product. When the computer program product is run on an electronic device, the electronic device is enabled to perform the notification message preview method according to any one of the implementations of the first aspect. 
     It may be understood that the electronic device according to the second aspect, the chip system according to the third aspect, the computer storage medium according to the fourth aspect, and the computer program product according to the fifth aspect are all configured to perform the corresponding method provided above. Therefore, for beneficial effects that can be achieved, refer to the beneficial effects in the foregoing corresponding method. Details are not described herein again. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1( a )  to  FIG. 1( c )  are application scenarios of displaying a notification message in the conventional technology: 
         FIG. 2  is a schematic diagram 1 of a structure of an electronic device according to an embodiment of this application; 
         FIG. 3  is a schematic diagram of an architecture of an operating system in an electronic device according to an embodiment of this application: 
         FIG. 4( a )  to  FIG. 4( c )  are scenario diagrams 1 of a notification message preview method according to an embodiment of this application; 
         FIG. 5( a )  to  FIG. 5( c )  are scenario diagrams 2 of a notification message preview method according to an embodiment of this application: 
         FIG. 6  is a scenario diagram 3 of a notification message preview method according to an embodiment of this application; 
         FIG. 7( a )  and  FIG. 7( b )  are scenario diagrams 4 of a notification message preview method according to an embodiment of this application: 
         FIG. 8( a )  and  FIG. 8( b )  are scenario diagrams 5 of a notification message preview method according to an embodiment of this application; 
         FIG. 9( a )  and  FIG. 9( b )  are scenario diagrams 6 of a notification message preview method according to an embodiment of this application: 
         FIG. 10( a )  and  FIG. 10( b )  are scenario diagrams 7 of a notification message preview method according to an embodiment of this application: 
         FIG. 11( a )  and  FIG. 11( b )  are scenario diagrams 8 of a notification message preview method according to an embodiment of this application; 
         FIG. 12( a )  and  FIG. 12( b )  are scenario diagrams 9 of a notification message preview method according to an embodiment of this application; 
         FIG. 13( a )  and  FIG. 13( b )  are scenario diagrams 10 of a notification message preview method according to an embodiment of this application; 
         FIG. 14( a )  and  FIG. 14( b )  are scenario diagrams 11 of a notification message preview method according to an embodiment of this application; 
         FIG. 15( a )  and  FIG. 15( b )  are scenario diagrams 12 of a notification message preview method according to an embodiment of this application; 
         FIG. 16( a )  and  FIG. 16( b )  are scenario diagrams 13 of a notification message preview method according to an embodiment of this application; 
         FIG. 17( a )  and  FIG. 17( b )  are scenario diagrams 14 of a notification message preview method according to an embodiment of this application: 
         FIG. 18( a )  and  FIG. 18( b )  are scenario diagrams 15 of a notification message preview method according to an embodiment of this application: 
         FIG. 19  is a schematic diagram of a structure of a chip system according to an embodiment of this application; and 
         FIG. 20  is a schematic diagram 2 of a structure of an electronic device according to an embodiment of this application. 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     The following describes implementations of embodiments in detail with reference to the accompanying drawings. 
     The embodiments of this application provide a notification message preview method, which may be applied to electronic devices such as a mobile phone, a tablet computer, a notebook computer, an ultra-mobile personal computer (ultra-mobile personal computer, UMPC), a handheld computer, a netbook, and a personal digital assistant (personal digital assistant, PDA), a wearable electronic device, or a virtual reality device. This is not limited in the embodiments of this application. 
     For example,  FIG. 2  is a schematic diagram of a structure of an electronic device  10 X). 
     The electronic device  100  may include a processor  110 , an external memory interface  120 , an internal memory  121 , a universal serial bus (universal serial bus, USB) interface  130 , a charging management module  140 , a power management module  141 , a battery  142 , an antenna  1 , an antenna  2 , a mobile communications module  150 , a wireless communications module  160 , an audio module  170 , a speaker  170 A, a receiver  170 B, a microphone  170 C, a headset jack  170 D, a sensor module  180 , a button  190 , a motor  191 , an indicator  192 , a camera  193 , a display  194 , a subscriber identification module (subscriber identification module, SIM) card interface  195 , and the like. 
     It may be understood that an example structure in the embodiments of the present invention does not constitute a specific limitation on the electronic device  100 . In other embodiments of this application, the electronic device  100  may include more or fewer components than those shown in the figure, or some components may be combined, or some components may be split, or there may be a different component layout. The components shown in the figure may be implemented by hardware, software, or a combination of software and hardware. 
     The processor  110  may include one or more processing units. For example, the processor  110  may include an application processor (application processor, AP), a modem processor, a graphics processing unit (graphics processing unit, GPU), an image signal processor (image signal processor, ISP), a controller, a video codec, a digital signal processor (digital signal processor, DSP), a baseband processor, and/or a neural-network processing unit (neural-network processing unit, NPU). Different processing units may be independent devices, or may be integrated into one or more processors. 
     The controller may generate an operation control signal based on instruction operation code and a time sequence signal, to complete control of instruction fetching and instruction execution. 
     A memory may further be disposed in the processor  110 , and is configured to store instructions and data. In some embodiments, the memory in the processor  110  is a cache memory. The memory may store instructions or data that has just been used or is cyclically used by the processor  110 . If the processor  110  needs to use the instructions or the data again, the processor  110  may directly invoke the instructions or the data from the memory. This avoids repeated access and reduces waiting time of the processor  110 . Therefore, system efficiency is improved. 
     In some embodiments, the processor  110  may include one or more interfaces. The interface may include an inter-integrated circuit (inter-integrated circuit, I2C) interface, an inter-integrated circuit sound (inter-integrated circuit sound, I2S) interface, a pulse code modulation (pulse code modulation, PCM) interface, a universal asynchronous receiver/transmitter (universal asynchronous receiver/transmitter, UART) interface, a mobile industry processor interface (mobile industry processor interface. MIPI), a general-purpose input/output (general-purpose input/output, GPIO) interface, a subscriber identification module (subscriber identity module. SIM) interface, a universal serial bus (universal serial bus, USB) interface, and/or the like. 
     The charging management module  140  is configured to receive a charging input from a charger. The charger may be a wireless charger or a wired charger. In some embodiments of wired charging, the charging management module  140  may receive a charging input from the wired charger through the USB interface  130 . In some embodiments of wireless charging, the charging management module  140  may receive a wireless charging input through a wireless charging coil of the electronic device  100 . The charging management module  140  may further supply power to the electronic device by using the power management module  141  when the battery  142  is charged. 
     The power management module  141  is configured to connect to the battery  142 , the charging management module  140 , and the processor  110 . The power management module  141  receives an input of the battery  142  and/or an input of the charging management module  140 , and supplies power to the processor  110 , the internal memory  121 , the display  194 , the camera  193 , the wireless communications module  160 , and the like. The power management module  141  may be further configured to monitor parameters such as a battery capacity, a battery cycle count, and a battery health status (electric leakage or impedance). In some other embodiments, the power management module  141  may alternatively be disposed in the processor  110 . In some other embodiments, the power management module  141  and the charging management module  140  may alternatively be disposed in a same device. 
     A wireless communication function of the electronic device  100  may be implemented through the antenna  1 , the antenna  2 , the mobile communications module  150 , the wireless communications module  160 , the modem processor, the baseband processor, and the like. 
     The antenna  1  and the antenna  2  are configured to transmit and receive electromagnetic wave signals. Each antenna in the electronic device  100  may be configured to cover one or more communication frequency bands. Different antennas may further be multiplexed, to improve antenna utilization. For example, the antenna  1  may be multiplexed as a diversity antenna in a wireless local area network. In some other embodiments, the antenna may be used in combination with a tuning switch. 
     The mobile communications module  150  may provide a solution that is for wireless communication including 2G/3G/4G/5G and the like and that is applied to the electronic device  100 . The mobile communications module  150  may include one or more filters, a switch, a power amplifier, a low noise amplifier (low noise amplifier, LNA), and the like. The mobile communications module  150  may receive an electromagnetic wave through the antenna  1 , perform processing such as filtering or amplification on the received electromagnetic wave, and transfer the electromagnetic wave to the modem processor for demodulation. The mobile communications module  150  may further amplify a signal modulated by the modem processor, and convert an amplified signal into an electromagnetic wave through the antenna  1  for radiation. In some embodiments, at least some function modules of the mobile communications module  150  may be disposed in the processor  110 . In some embodiments, at least some function modules of the mobile communications module  150  and at least some modules of the processor  110  may be disposed in a same device. 
     The modem processor may include a modulator and a demodulator. The modulator is configured to modulate a to-be-sent low-frequency baseband signal into a medium-high frequency signal. The demodulator is configured to demodulate a received electromagnetic wave signal into a low frequency baseband signal. Then, the demodulator transfers the low-frequency baseband signal obtained through demodulation to the baseband processor for processing. The low-frequency baseband signal is processed by the baseband processor, and is then transferred to the application processor. The application processor outputs a sound signal through an audio device (which is not limited to the speaker  170 A, the receiver  170 B, or the like), or displays an image or a video through the display  194 . In some embodiments, the modem processor may be an independent component. In some other embodiments, the modem processor may be independent of the processor  110 , and is disposed in a same device as the mobile communications module  150  or another function module. 
     The wireless communications module  160  may provide a wireless communication solution that includes wireless local area networks (wireless local area networks, WLAN) (for example, a wireless fidelity (wireless fidelity, Wi-Fi) network), Bluetooth (Bluetooth, BT), a global navigation satellite system (global navigation satellite system, GNSS), frequency modulation (frequency modulation, FM), near field communication (near field communication, NFC), an infrared (infrared, IR) technology, or the like and that is applied to the electronic device  100 . The wireless communications module  160  may be one or more components integrating one or more communications processor modules. The wireless communications module  160  receives an electromagnetic wave through the antenna  2 , performs frequency modulation and filtering processing on an electromagnetic wave signal, and sends a processed signal to the processor  110 . The wireless communications module  160  may further receive a to-be-sent signal from the processor  110 , perform frequency modulation and amplification on the signal, and convert the signal into an electromagnetic wave through the antenna  2  for radiation. 
     In some embodiments, in the electronic device  100 , the antenna  1  is coupled to the mobile communications module  150 , and the antenna  2  is coupled to the wireless communications module  160 , so that the electronic device  100  can communicate with a network and another device by using a wireless communications technology. The wireless communications technology may include a global system for mobile communications (global system for mobile communications, GSM), a general packet radio service (general packet radio service, GPRS), code division multiple access (code division multiple access, CDMA), wideband code division multiple access (wideband code division multiple access, WCDMA), time-division code division multiple access (time-division code division multiple access, TD-CDMA), long term evolution (long term evolution, LTE). BT, a GNSS, a WLAN, NFC, FM, an IR technology, and/or the like. The GNSS may include a global positioning system (global positioning system, GPS), a global navigation satellite system (global navigation satellite system. GLONASS), a Beidou navigation satellite system (beidou navigation satellite system, BDS), a quasi-zenith satellite system (quasi-zenith satellite system, QZSS), and/or a satellite based augmentation system (satellite based augmentation systems, SBAS). 
     The electronic device  100  implements a display function through the GPU, the display  194 , the application processor, and the like. The GPU is a microprocessor for image processing, and is connected to the display  194  and the application processor. The GPU is configured to perform mathematical and geometric calculation, and render an image. The processor  110  may include one or more GPUs that execute a program instruction to generate or change display information. 
     The display  194  is configured to display an image, a video, and the like. The display  194  includes a display panel. The display panel may be a liquid crystal display (liquid crystal display, LCD), an organic light-emitting diode (organic light-emitting diode, OLED), an active-matrix organic light emitting diode (active-matrix organic light emitting diode, AMOLED), a flexible light-emitting diode (flex light-emitting diode, FLED), a mini-LED, a micro-LED, a micro-OLED, quantum dot light emitting diodes (quantum dot light emitting diodes, QLED), or the like. In some embodiments, the electronic device  100  may include one or N displays  194 , where N is a positive integer greater than 1. 
     The electronic device  100  may implement a photographing function through the ISP, the camera  193 , the video codec, the GPU, the display  194 , the application processor, and the like. 
     The ISP is configured to process data fed back by the camera  193 . For example, during photographing, a shutter is turned on, and light is transmitted to a photosensitive element of the camera through a lens. An optical signal is converted into an electrical signal, the photosensitive element of the camera transmits the electrical signal to the ISP for processing, and the electrical signal is converted into an image that can be seen. The ISP may further optimize an algorithm for noise, brightness, and complexion of an image. The ISP may further optimize parameters such as exposure and a color temperature of a shooting scenario. In some embodiments, the ISP may be disposed in the camera  193 . 
     The camera  193  is configured to capture a static image or a video. An optical image of an object is generated through the lens, and is projected to the photosensitive element. The photosensitive element may be a charge coupled device (charge coupled device, CCD) or a complementary metal-oxide-semiconductor (complementary metal-oxide-semiconductor, CMOS) phototransistor. The photosensitive element converts the optical signal into the electrical signal, and then transmits the electrical signal to the ISP to convert the electrical signal into a digital image signal. The ISP outputs the digital image signal to the DSP for processing. The DSP converts the digital image signal into a standard image signal in a format such as RGB or YUV. In some embodiments, the electronic device  100  may include one or N cameras  193 , where N is a positive integer greater than 1. 
     The digital signal processor is configured to process a digital signal. In addition to the digital image signal, the digital signal processor may further process another digital signal. For example, when the electronic device  100  selects a frequency, the digital signal processor is configured to perform Fourier transformation and the like on frequency energy. 
     The video codec is configured to compress or decompress a digital video. The electronic device  100  may support one or more video codecs. Therefore, the electronic device  100  may play or record videos in a plurality of coding formats, for example, moving picture experts group (moving picture experts group, MPEG)-1, MPEG-2, MPEG-3, and MPEG-4. 
     The NPU is a neural-network (neural-network. NN) computing processor that rapidly processes input information by referring to a structure of a biological neural network, for example, by referring to a transfer mode between human brain neurons, and can further perform self-learning continuously. The NPU can implement applications such as intelligent cognition of the electronic device  100 , such as image recognition, facial recognition, speech recognition, and text understanding. 
     The external memory interface  120  may be configured to connect to an external memory card, for example, a micro SD card, to extend a storage capability of the electronic device  100 . The external memory card communicates with the processor  110  through the external memory interface  120 , to implement a data storage function. For example, files such as music and a video are stored in the external storage card. 
     The internal memory  121  may be configured to store one or more computer programs, where the one or more computer programs include instructions. The processor  110  may run the instructions stored in the internal memory  121 , so that the electronic device  100  performs the notification message preview method provided in some embodiments of this application, various function applications, data processing, and the like. The internal memory  121  may include a program storage area and a data storage area. The program storage area may store an operating system. The program storage area may further store one or more applications (for example, gallery and contacts), and the like. The data storage area may store data (for example, a photo and a contact) created during use of the electronic device  101 , and the like. In addition, the internal memory  121  may include a high-speed random access memory, or may include a nonvolatile memory, for example, one or more magnetic disk storage devices, a flash memory device, or a universal flash storage (universal flash storage, UFS). In some other embodiments, the processor  110  runs the instructions stored in the internal memory  121  and/or the instructions stored in the memory disposed in the processor, so that the electronic device  100  performs the notification message preview method provided in the embodiments of this application, various function applications, and data processing. 
     The electronic device  100  may implement audio functions, for example, music playing and recording, by using the audio module  170 , the speaker  170 A, the receiver  170 B, the microphone  170 C, the headset jack  170 D, the application processor, and the like. 
     The audio module  170  is configured to convert digital audio information into an analog audio signal output, and is further configured to convert an analog audio input into a digital audio signal. The audio module  170  may be further configured to code and decode an audio signal. In some embodiments, the audio module  170  may be disposed in the processor  110 , or some function modules of the audio module  170  are disposed in the processor  110 . 
     The speaker  170 A, also referred to as a “horn”, is configured to convert an audio electrical signal into a sound signal. The electronic device  100  may listen to music or answer a hands-free call by using the speaker  170 A. 
     The receiver  170 B, also referred to as an “earpiece”, is configured to convert an audio electrical signal into a sound signal. When the electronic device  100  answers a call or receives voice information, the receiver  170 B may be placed near a human ear to listen to a voice. 
     The microphone  170 C, also referred to as a “mike” or a “voice transmitter”, is configured to convert a sound signal into an electrical signal. When making a call or sending a voice message, the user may make a sound near the microphone  170 C by the mouth of the user, to input the sound signal to the microphone  170 C. One or more microphones  170 C may be disposed in the electronic device  100 . In some other embodiments, two microphones  170 C may be disposed in the electronic device  100 , to collect a sound signal and implement a noise reduction function. In some other embodiments, three, four, or more microphones  170 C may alternatively be disposed in the electronic device  100 , to collect a sound signal, reduce a noise, identify a sound source, implement a directional recording function, and the like. 
     The headset jack  170 D is configured to connect to a wired headset. The headset jack  170 D may be the USB interface  130 , or a 3.5 mm open mobile terminal platform (open mobile terminal platform, OMTP) standard interface, or a cellular telecommunications industry association of the USA (cellular telecommunications industry association of the USA, CTIA) standard interface. 
     The sensor module  180  may include a pressure sensor  180 A, a gyroscope sensor  180 B, a barometric pressure sensor  180 C, a magnetic sensor  180 D, an acceleration sensor  180 E, a distance sensor  180 F, an optical proximity sensor  180 G, a fingerprint sensor  180 H, a temperature sensor  180 J, a touch sensor  180 K, an ambient light sensor  180 L, a bone conduction sensor  180 M, and the like. 
     In addition, the electronic device may further include one or more components such as a button  190 , a motor  191 , an indicator  192 , and a SIM card interface  195 . This is not limited in the embodiments of this application. 
     A software system of the electronic device  100  may use a layered architecture, an event-driven architecture, a microkernel architecture, a micro service architecture, or a cloud architecture. In the embodiments of this application, an Android system with a layered architecture is used as an example to describe a software structure of the electronic device  100 . 
       FIG. 3  is a block diagram of the software structure of the electronic device  100  according to an embodiment of this application. 
     In the layered architecture, software is divided into several layers, and each layer has a clear role and task. The layers communicate with each other through a software interface. In some embodiments, the Android system is divided into four layers: an application layer, an application framework layer, an Android runtime (Android runtime) and a system library, and a kernel layer from top to bottom. 
     1. Application Layer 
     The application layer may include a series of applications. 
     As shown in  FIG. 3 , the applications may include applications (application, APP) such as Phone, Contacts, Camera, Gallery, Calendar, Map, Navigation, Bluetooth, Music, Video, and Messages. 
     In the embodiments of this application, the application package may further include systemUI, which is a core application of the Android system Generally, the systemUI runs in the Android system as an application. That is, an APK file is generated when the systemUI module is compiled. A source code path of the systemUI is frameworks/base/packages/systemUI/, and an installation path is system/priv-app/-systemUI. 
     The systemUI can be used to manage a plurality of modules displayed on the electronic device, such as a status bar (status bar), a navigation bar (navigation bar), a notification panel (notification panel), recents (a recent task interface), and keyguard (a lock screen). 
     2. Application Framework Layer 
     The application framework layer provides an application programming interface (application programming interface, API) and a programming framework for the applications at the application layer. The application program framework layer includes some predefined functions. 
     The modules in the systemUI typically reside at the application framework layer as services (services) when running. For example, when the lock screen is displayed, the systemUI can start a keyguard service to display a notification message on the lock screen. When the notification panel is displayed, the systemUI can start a systembars service to display a notification message in the notification panel. 
     As shown in  FIG. 3 , the application framework layer may include a notification manager (notification manager). The notification manager enables an application to display notification information in the status bar or the notification panel. The notification information may convey a notification-type message, and may automatically disappear after being displayed for a short period of time. For example, the notification manager is configured to notify download completion, provide a message notification, and the like. 
     A WeChat app is used as an example. If the WeChat app running in the background receives a chat message 1 sent by a contact A, a notification object (notification object) may be first instantiated. For example, the notification object may include information such as a profile picture of the contact A, a name of the contact A, and content and receiving time of the chat message 1. The information is used as content that needs to be displayed in a notification message of the chat message 1. Further, the WeChat app may invoke a related interface (for example, a notify( ) interface) of the notification manager to transfer the created notification object as a parameter to the notification manager. 
     In addition, a notification panel service in the systemUI can listen for changes to notification objects in the notification manager. When a new notification object is detected in the notification manager, the notification panel service may generate a notification message corresponding to the chat message 1. Further, the notification panel service may display the notification message in the notification panel or the lock screen by using the system application: systemUI. 
     In the embodiments of this application, the systemUI may display a plurality of notification messages in a form of a message group. The message group may include the plurality of notification messages. For example, a plurality of notification messages from a same application may be set as a message group. For another example, a plurality of notification messages of a same type (for example, an advertisement type or a social type) may be set as a message group. 
     For example, the message group may be in three display states: a collapsed state, a preview state, and an expanded state. 
     As shown in  FIG. 4( a ) , after detecting an operation performed by the user to open a notification panel, the systemUI may display a first interface  301 . The first interface  301  includes a notification panel  302 , the notification panel  302  includes a message group  303  of a WeChat app, and the message group  303  includes three notification messages from the WeChat app. In this case, the message group  303  is in a collapsed state. The message group  303  in the collapsed state means that only one notification message in the message group  303  is displayed on a card  300 , and other notification messages in the message group  303  are hidden. For example, still as shown in  FIG. 4( a ) , the card  300  includes only a notification message that is recently received by the WeChat app from a contact Sam. Certainly, an unread indicator  304  may be further set in the message group  303 , and the unread indicator  304  may indicate that there are two hidden notification messages in the message group  303 . 
     If it is detected that the user enters a first operation to the message group  303 , as shown in  FIG. 4( b ) , the systemUI may display the message group  303  in a preview state. The message group  303  in the preview state means that a plurality of notification messages in the message group  303  are displayed on one card (for example, a card  305 ), and the card  305  includes the notification message displayed by the systemUI in the collapsed state. Still as shown in  FIG. 4( b ) , the card  305  may include one notification message that is received by the WeChat app from the contact Sam and two notification messages that are received by the WeChat app from a contact Jack. The user may quickly view the plurality of notification messages in the message group  303  on the card  305 , and the user may centrally manage the plurality of notification messages in the message group  303  on the card  305 . For example, the systemUI may display, on the card  305 , names of contacts, profile pictures of contacts, message content summaries, and the like corresponding to the notification messages in the message group  303 . 
     When the message group  303  is displayed in the preview state, if it is detected that the user enters a second operation to the message group  303 , as shown in  FIG. 4( c ) , the systemUI may display the message group  303  in the expanded state. The message group  303  in the expanded state means that each notification message in the message group  303  is correspondingly displayed on one card. Still as shown in  FIG. 4( c ) , after the message group  303  of the WeChat app is expanded, the systemUI may display a card  306  to a card  308 , where the card  306  includes one notification message from the contact Sam, the card  307  includes one notification message from the contact Jack, and the card  308  includes the other notification message from the contact Jack. The user may manage a corresponding notification message on each card, for example, expand the notification message, delete the notification message, or mark the notification message as read. In addition, detailed content such as receiving time of the corresponding notification message may be further displayed on each card. 
     It should be noted that a display state of the message group  303  may be randomly switched between the collapsed state, the preview state, and the expanded state. 
     For example, when the message group  303  is displayed in the expanded state, the user may further enter a third operation to switch the message group  303  from the expanded state to the collapsed state. Alternatively, when the message group  303  is displayed in the expanded state, the user may further enter a fourth operation to switch the message group  303  from the expanded state to the preview state. Alternatively, when the message group  303  is displayed in the preview state, the user may enter a fifth operation to switch the message group  303  from the preview state to the collapsed state. Alternatively, when the message group  303  is displayed in the collapsed state, the user may enter a sixth operation to switch the message group  303  from the collapsed state to the expanded state. 
     That is, when notification messages of a message group type are displayed, a new display state, namely, the preview state, is added between the collapsed state and the expanded state in the embodiments of this application. When the message group is in the collapsed state, the electronic device displays a content summary of only one notification message in the message group to the user. Alternatively, when the message group is in the preview state, the electronic device may display content summaries of the notification messages in the message group to the user by using the message group as a unit. Alternatively, when the message group is in the expanded state, the electronic device may display detailed content of the notification messages to the user by using each notification message as a unit. 
     In this way, when viewing the message group in the notification panel, the user may switch the message group to the preview state and quickly preview the plurality of notification messages in the message group without expanding each notification message in the message group to view and manage each notification message. This improves management efficiency and usage experience of the user on the message group. 
     Certainly, the application framework layer may further include an activity manager, a window manager, a content provider, a view system, a resource manager, an input method manager, and the like. 
     The activity manager can be configured to manage a life cycle of each application. An application usually runs in an operating system in a form of an activity. The activity manager can schedule an activity process of an application to manage the life cycle of each application. The window manager is configured to manage a window program. The window manager may obtain a size of a display, determine whether there is a status bar, lock a screen, take a screenshot, and the like. The content provider is configured to store and obtain data, and enable the data to be accessed by an application. The data may include a video, an image, audio, calls that are made and answered, a browsing history and a bookmark, a phone book, and the like. The view system includes visual controls such as a control for displaying a text and a control for displaying a picture. The view system may be configured to construct an application. The display interface may include one or more views. For example, a display interface including an SMS message notification icon may include a view for displaying a text and a view for displaying a picture. The resource manager provides various resources for an application, such as a localized character string, an icon, a picture, a layout file, and a video file. 
     3. Android Runtime and System Library 
     The Android runtime includes a kernel library and a virtual machine. The Android runtime is responsible for scheduling and management of the Android system. 
     The kernel library includes two parts: a function that needs to be invoked by the Java language and a kernel library of Android. 
     The application program layer and the application program framework layer run on the virtual machine. The virtual machine executes a Java file at the application program layer and the application program framework layer as a binary file. The virtual machine is configured to perform functions such as object life cycle management, stack management, thread management, security and exception management, and garbage collection. 
     The system library may include a plurality of function modules, for example, a surface manager (surface manager), media libraries (Media Libraries), a three-dimensional graphics processing library (for example, OpenGL ES), and a 2D graphics engine (for example, SGL). 
     The surface manager is configured to manage a display subsystem, and provide fusion of 2D and 3D layers for a plurality of applications. The media library supports playback and recording in a plurality of commonly used audio and video formats, static image files, and the like. The media library may support a plurality of audio and video coding formats such as MPEG-4, H.264, MP3, AAC, AMR, JPG, and PNG. The three-dimensional graphics processing library is configured to implement three-dimensional graphics drawing, image rendering, composition, layer processing, and the like. The 2D graphics engine is a drawing engine for 2D drawing. 
     4. Kernel Layer 
     The kernel layer is a layer between hardware and software. The kernel layer includes at least a display driver, a camera driver, an audio driver, a sensor driver, and the like. This is not limited in the embodiments of this application. 
     For example, a mobile phone is an electronic device. The following describes in detail the notification message preview method provided in the embodiments of this application with reference to the accompanying drawings. 
     Generally, there may be a plurality of entrances in the mobile phone that can display a notification message. For example, as shown in  FIG. 5( a ) , the mobile phone may set a notification panel  402  (which may also be referred to as a message center, a notification panel, or the like) in a drop-down menu  401 . The mobile phone may display notification messages of applications in the notification panel  402 . For another example, as shown in  FIG. 5( b ) , the mobile phone may display the notification messages of the applications on a lock screen  403 . Alternatively, as shown in  FIG. 5( c ) , the mobile phone may further display the notification messages of the applications in a menu  404  on a leftmost screen. Display positions of the notification messages are not limited in the embodiments of this application. 
     The notification messages displayed in the notification panel  402  are used as examples. When the mobile phone receives the plurality of notification messages, the plurality of notification messages may be displayed in the notification panel  402  in a form of a message group. For example, the mobile phone may set a plurality of notification messages of a same application as a message group. Alternatively, the mobile phone may set notification messages of a same type as a message group. For example, the mobile phone may set all notification messages of unread chat messages as a message group, and set all notification messages of version updates as another message group. 
     As shown in  FIG. 6 , after receiving a plurality of notification messages from a WeChat app, the mobile phone may display a message group  405  of the WeChat app in the notification panel  402 . In addition, the notification panel  402  further includes a notification message  406  of a Weather app and a notification message  407  of a Phone app. 
     In the embodiments of this application, when the message group  405  is displayed, the message group  405  may be in three display states: a collapsed state, a preview state, or an expanded state. The mobile phone can switch the message group between the three display states. 
     Still as shown in  FIG. 6 , the mobile phone may display the message group  405  in the collapsed state by default when the user opens the notification panel  402 . When the message group  405  is in the collapsed state, the mobile phone may display only one notification message in the message group  405  on a card  501 . For example, the mobile phone may display, on the card  501 , a notification message  502  recently received by the WeChat app from a contact (for example, Sam). The mobile phone may further display a profile picture of the contact Sam corresponding to the notification message  502 , receiving time of the notification message  502 , and the like. In addition, the mobile phone may further display, on the card  501 , a quantity of remaining notification messages that are hidden in the message group  405 . For example, in addition to the notification message  502  from the contact Sam, the message group  405  shown in  FIG. 6  further includes four remaining notification messages that are hidden. 
     It should be noted that, when displaying the notification message  502  on the card  501 , the mobile phone may display, in the notification message  502 , all chat content sent by the contact Sam, or some chat content sent by the contact Sam. For example, if the chat content sent by the contact Sam in the WeChat app is “Let&#39;s play ball tonight. I&#39;ll wait for you on the basketball court”, the mobile phone may display the first 10 characters of the chat content (that is, “Let&#39;s play ball tonight”) in the notification message  502 . 
     When the message group  405  is in the collapsed state, the user may manage the message group  405  by using the message group  405  as a unit. 
     For example, as shown in  FIG. 7( a ) , the user may enter a swipe right operation to the card  501  on which the message group  405  is located. As shown in  FIG. 7( b ) , after detecting the swipe right operation performed by the user on the card  501 , the mobile phone may delete the message group  405  in the notification panel  402 . In this case, the message group  405  is no longer displayed in the notification panel  402 . It may be understood that the user deletes only five notification messages from the WeChat app in the notification panel  402 , and the user may still find five unread chat messages corresponding to the five notification messages in the WeChat app. 
     For another example, as shown in  FIG. 8( a ) , the user may enter a swipe left operation to the card  501  on which the message group  405  is located. After detecting the swipe left operation performed by the user on the card  501 , the mobile phone may display a management button  701 . If the mobile phone detects that the user selects the management button  701 , as shown in  FIG. 8( b ) , the mobile phone may display a management menu  702  of the message group  405 . The management menu  702  may include an option of deleting the message group  405 , an option of marking the message group  405  as read, an option of expanding the message group  405 , and the like. That is, in the collapsed state, the user may manage, by using the management menu  702 , the plurality of notification messages in the message group  405  by using the message group  405  as a unit. 
     Certainly, if the mobile phone detects that the user taps the management button  701 , the mobile phone may also display a setting interface for notification management in a Settings app. The user may manually set, in the setting interface, options related to the notification messages, such as display positions, display modes, and display rules of the notification messages in the notification panel. 
     In some embodiments, when the message group  405  is in the collapsed state, in response to a first operation performed by the user on the message group  405 , the mobile phone may switch the message group  405  from the collapsed state to the preview state. For example, the first operation may be any gesture such as a touch and hold operation, a double-tap operation, a press operation, or a knock operation. This is not limited in the embodiments of this application. 
     For example, the first operation is the touch and hold operation. As shown in  FIG. 9( a ) , the user may enter the touch and hold operation to the message group  405  (namely, the card  501 ) in the collapsed state. After the mobile phone detects the touch and hold operation performed by the user on the card  501 , as shown in  FIG. 9( b ) , the mobile phone may expand the card  501  in the notification panel  402 , and centrally display the plurality of notification messages in the message group  405  on the expanded card  501 . The expanded card  501  includes the notification message  502  displayed when the card  501  is collapsed. For example, the mobile phone may display, on the expanded card  501 , all notification messages (for example, a notification message  801  to a notification message  805 ) in the message group  405  from the WeChat app. In this case, the message group  405  is in the preview state. Still as shown in  FIG. 9( b ) , when expanding the card  501 , the mobile phone may simultaneously move a notification message  406  of the Weather app and a notification message  407  of the Phone app downwards. That is, in the preview state, the card  501  on which the message group  405  is located and cards on which other notification messages are located may be located in a same interface. 
     When the message group  405  is in the preview state, still as shown in  FIG. 9( b ) , the user may preview, on the card  501 , the notification message  801  and the notification message  802  from the contact Sam, the notification message  803  from the contact Jack, and the notification message  804  and the notification message  805  from a contact Alice, namely, the five notification messages included in the message group  405 . For example, the mobile phone may display the five notification messages on the card  501  from earliest to latest. Certainly, the mobile phone may alternatively sort the five notification messages based on a category of the contacts or content of the notification messages. This is not limited in the embodiments of this application. 
     For example, when the message group  405  is in the preview state, to save display space, the mobile phone may display a content summary of each notification message on the card  501 . For example, the mobile phone may display content in the first line of each of the notification messages  801  to  805 . That is, the notification content displayed in the notification message  801  to the notification message  805  may be incomplete. Certainly, the mobile phone may further display information such as a profile picture and a nickname of a contact corresponding to each notification message. 
     In some other embodiments, as shown in  FIG. 10( a )  and  FIG. 10( b ) , after the mobile phone detects the touch and hold operation performed by the user on the card  501 , the mobile phone may recreate a card  901  over the notification panel  402 , and display, on the card  901 , the five notification messages in the message group  405  from the WeChat app. In this case, the notification panel  402  is located in an interface under the card  901 , and content and a position of each card in the notification panel  402  do not change. The card  901  is similar to the card  501  shown in  FIG. 9( b ) . In this case, the message group  405  is also in the preview state. 
     For example, when the message group  405  is in the preview state shown by the card  901 , the mobile phone may dim, blur, or hide the display interface (namely, the drop-down menu in which the notification panel  402  is located) under the card  901 . This prompts the user to focus on reading each notification message on the card  901 . 
     In other words, the embodiments of this application provide two display modes of the message group  405  in the preview state. Certainly, a person skilled in the art may set the display modes of the message group in the preview state based on actual experience or an actual application scenario. This is not limited in the embodiments of this application. 
     It can be learned that, when the message group is in the collapsed state, by using one touch and hold operation, the user may switch the message group from the collapsed state to the preview state. In the preview state, the mobile phone can display the content of the plurality of notification messages in the message group to the user. This facilitates the user to quickly preview the notification messages in the message group and simplifies an operation process of viewing related notification messages in the message group by the user. 
     The expanded card  501  is still used as an example. After the plurality of notification messages in the message group  405  are displayed on the card  501  by using the touch and hold operation that is performed by the user, the user may continue to perform the touch and hold operation. As shown in  FIG. 11( a ) , before detecting that the finger of the user leaves the screen of the mobile phone (that is, the touch and hold operation ends), the mobile phone may continuously display the message group  405  in the preview state. After detecting that the finger of the user leaves the screen of the mobile phone (that is, the touch and hold operation ends), as shown in  FIG. 11( b ) , the mobile phone may switch the message group  405  back to the collapsed state. In this way, by using only one touch and hold operation, the user may trigger the mobile phone to switch the message group  405  from the collapsed state to the preview state, and switch the message group  405  from the preview state back to the collapsed state. This simplifies an operation process of switching the message group between the plurality of display states by the user. 
     In addition, the expanded card  501  is still used as an example. A size of the expanded card  501  may be dynamically set according to a quantity of notification messages in the message group  405 . Alternatively, the mobile phone may set the expanded card  501  to a fixed size. When the size of the expanded card  501  is fixed, as shown in  FIG. 12( a )  and  FIG. 12( b ) , if the quantity of notification messages in the message group  405  is relatively large, all notification messages cannot be completely displayed on the card  501 . In this case, while performing the touch and hold operation, the user may further enter a swipe operation by using another finger or a stylus. In this case, in response to the swipe operation, the mobile phone may display, on the card  501  in scrolling mode, other notification messages in the message group  405  that are not displayed. 
     Alternatively, when the notification messages in the message group  405  cannot be completely displayed on the expanded card  501 , the mobile phone may automatically display the notification messages in the message group  405  in scrolling mode on the card  501 . This is not limited in the embodiments of this application. Alternatively, the mobile phone may set a specific policy to use a plurality of notification messages in the message group  405  as notification messages that need to be displayed in the preview state. For example, the mobile phone may set to use a plurality of notification messages that are received within the last hour as notification messages that need to be displayed in the preview state. In this case, after detecting that the user enters the touch and hold operation to the message group  405  that is in the collapsed state, the mobile phone may expand the card  501 , and display, on the card  501 , the plurality of notification messages that are received within the latest hour. 
     In some embodiments, when the message group  405  is in the preview state, the user may still manage the notification messages in the message group  405  by using the message group  405  as a unit. 
     For example, as shown in  FIG. 13( a ) , after the plurality of notification messages in the message group  405  are displayed on the card  501  by using the touch and hold operation that is performed by the user, the finger of the user does not need to leave the screen, and may continue to enter a swipe right operation to the expanded card  501 . As shown in  FIG. 13( b ) , after detecting that the user swipes the expanded card  501  rightwards, the mobile phone may delete the card  501  in the notification panel  402 . In this case, all the notification messages on the card  501  are deleted. 
     For another example, as shown in  FIG. 14( a ) , after the plurality of notification messages in the message group  405  are displayed on the card  501  by using the touch and hold operation that is performed by the user, the finger of the user does not need to leave the screen, and may continue to enter a swipe left operation to the expanded card  501 . After detecting that the user swipes the expanded card  501  leftwards, the mobile phone may display a management button  1201 . If the mobile phone detects that the user selects the management button  1201 , as shown in  FIG. 14( b ) , the mobile phone may display a management menu  1202  of the message group  405 . The management menu  1202  may include an option of deleting the message group  405 , an option of marking the message group  405  as read, an option of expanding the message group  405 , and the like. That is, in the preview state, the user may manage, by using the management menu  1202 , the plurality of notification messages in the message group  405  by using the message group  405  as a unit. 
     In some other embodiments, when the message group  405  is in the preview state, the user may further perform an operation on one notification message in the message group  405 . 
     For example, as shown in  FIG. 15( a ) , after the plurality of notification messages in the message group  405  are displayed on the card  501  by using the touch and hold operation that is performed by the user, the finger of the user does not need to leave the screen. If the mobile phone detects that time spent by the finger of the user on one notification message on the card  501  exceeds preset time. For example, after the mobile phone detects that the finger of the user stays on the notification message  802  for more than 2 seconds, as shown in  FIG. 15( b ) , the mobile phone may display detailed content  1301  of the notification message  802 . For example, the mobile phone may expand the notification message  802  on the card  501 , to display the detailed content  1301  of the notification message  802 . For another example, the mobile phone may also create a card on the card  501  to display the detailed content  1301  of the notification message  802 . This is not limited in the embodiments of this application. 
     Alternatively, after the mobile phone displays the plurality of notification messages in the message group  405  on the card  501 , if the mobile phone detects that the finger of the user performs a press operation on one notification message on the card  501 , as shown in  FIG. 15( b ) , the mobile phone may also display the detailed content  1301  of the notification message  802 . That is, after switching the message group to the preview state for previewing, the user may further select one notification message in the message group to view detailed content of this notification message. In this way, the user may quickly view detailed content of one notification message in the message group without expanding the entire message group. 
     In some embodiments, when the message group  405  is in the preview state, in response to a second operation performed by the user on the message group  405 , the mobile phone may switch the message group  405  from the preview state to the expanded state. The second operation may be any operation different from the first operation. 
     For example, the second operation may be a swipe up operation or a swipe down operation. The expanded card  501  is still used as an example. After the plurality of notification messages in the message group  405  are displayed on the card  501  by using the touch and hold operation that is performed by the user, if the mobile phone detects that the finger of the user continues to touch and hold the screen of the mobile phone, the mobile phone may continue to display the expanded card  501 . After the card  501  is expanded, as shown in  FIG. 16( a ) , if the mobile phone detects that the finger of the user enters the swipe down operation on the screen of the mobile phone, the mobile phone may switch the message group  405  from the preview state to the expanded state. 
     For example, as shown in  FIG. 16( b ) , when the message group  405  is in the expanded state, the mobile phone may display, in the notification panel  402 , each notification message in the message group  405  in a form of a card. That the message group  405  includes five notification messages from the WeChat app is still used as an example. After expanding the message group  405 , the mobile phone may delete the card  501  that is displayed when the message group  405  is in the expanded state, and generate a card  1401  to a card  1405 . The mobile phone may display each notification message in the message group  405  on each of the card  1401  to the card  1405 . In addition, the mobile phone may display detailed content of each notification message on a corresponding card. For example, the detailed content on each card may include specific time at which a contact sends a chat message, specific content of a chat message, a name and a profile picture of a contact, and the like. 
     It can be learned that, when the message group  405  is in the collapsed state, by using the touch and hold operation, the user may trigger the mobile phone to switch the message group  405  from the collapsed state to the preview state. Further, the finger of the user does not need to leave the screen of the mobile phone, and may continue to enter a swipe down operation to trigger the mobile phone to switch the message group  405  from the preview state to the expanded state. In this case, for the user, in an operation process from touching the screen of the mobile phone to leaving the screen of the mobile phone by the finger, the user may control the mobile phone to switch the message group  405  in the three display states: the collapsed state, the preview state, and the expanded state. This simplifies an operation process of switching the message group between the plurality of display states by the user, and improves user experience. 
     When the message group  405  is in the expanded state, the mobile phone may manage the plurality of notification messages in the message group  405  by using each notification message as a unit. 
     For example, as shown in  FIG. 17( a ) , after the message group  405  is expanded, each notification message in the message group may be displayed on each of the card  1401  to the card  1405 . If the mobile phone detects that the user swipes the card  1401  rightwards, the mobile phone may delete the card  1401  and the notification message on the card  1401 . In this case, the remaining four notification messages in the message group  405  are still displayed on the card  1402  to the card  1405 . 
     For another example, as shown in  FIG. 17( b ) , if the mobile phone detects that the user swipes the card  1401  leftwards, the mobile phone may display a management button  1501  of the card  1401 . If the mobile phone detects that the user selects the management button  1501 , the mobile phone may display a management menu  1502  corresponding to the card  1401 . The management menu  1502  may include an option of deleting the card  1401 , an option of marking the notification message on the card  1401  as read, and the like. That is, in the expanded state, the user may manage each notification message in the message group  405  by using the management menu  1502  of each notification message. 
     In addition, the user may switch the message group  405  from the expanded state to the collapsed state or the preview state. For example, as shown in  FIG. 18( a ) , after the mobile phone expands the message group  405 , each notification message in the group is displayed on each of the card  1401  to the card  1405 . The mobile phone may display a collapse button  1601  near the card  1401  that is located at the top (or the card  1405  that is located at the bottom). If the mobile phone detects that the user touches and holds the collapse button  1601 , the mobile phone may switch the message group  405  to the preview state. In this case, the mobile phone may display the message group  405  as the card  901  shown in  FIG. 10( b )  or the card  501  shown in  FIG. 9( b ) . 
     Correspondingly, if the mobile phone detects that the user taps the collapse button  1601 , as shown in  FIG. 18( b ) , the mobile phone may switch the message group  405  to the collapsed state. In this case, the mobile phone displays only one notification message in the message group  405 . Similarly, as shown in  FIG. 17( b ) , when the message group  405  is in the collapsed state, the mobile phone may set an expand button  1602  corresponding to the message group  405 . If the mobile phone detects that the user taps the expand button  1602 , the mobile phone may switch the message group  405  to the expanded state. In this case, the mobile phone may display the message group  405  as the interface shown in  FIG. 17( a ) . 
     It can be learned that, when the mobile phone displays the notification messages of the message group type, a display mode, namely, the preview state, is added between the collapsed state and the expanded state. In the preview state, the mobile phone can display the plurality of notification messages in the message group to the user, so that the user can quickly preview the notification messages in the message group. In addition, in the preview state, the user may further manage all the notification messages in the entire message group at a granularity of a message group. This improves management efficiency and usage experience of the user on the message group. 
     The embodiments of this application disclose a chip system. As shown in  FIG. 19 , the chip system includes at least one processor  1901  and at least one interface circuit  1902 . The processor  1901  and the interface circuit  1902  may be interconnected through a line. For example, the interface circuit  1902  may be configured to receive a signal from another apparatus (for example, a memory). For another example, the interface circuit  1902  may be configured to send a signal to another apparatus (for example, the processor  1901 ). For example, the interface circuit  1902  may read instructions stored in the memory, and send the instructions to the processor  1901 . When the instructions are executed by the processor  1901 , the electronic device is enabled to perform the steps in the foregoing embodiments. Certainly, the chip system may further include another discrete device. This is not specifically limited in the embodiments of this application. 
     The embodiments of this application disclose an electronic device, including a processor, and a memory, an input device, and an output device that are connected to the processor. The input device and the output device may be integrated into one device. For example, a touch-sensitive surface may be used as the input device, a display may be used as the output device, and the touch-sensitive surface and the display may be integrated into a touchscreen. 
     In this case, as shown in  FIG. 20 , the electronic device may include a touchscreen  2001 . The touchscreen  2001  includes a touch-sensitive surface  2006 , a display  2007 , one or more processors  2002 , a memory  2003 , one or more application programs (not shown), and one or more computer programs  2004 . The foregoing devices may be connected through one or more communications buses  2005 . The one or more computer programs  2004  are stored in the memory  2003  and are configured to be executed by the one or more processors  2002 . The one or more computer programs  2004  include instructions, and the instructions may be used to perform the steps in the foregoing embodiments. All related content of the steps in the foregoing method embodiments may be cited in function descriptions of corresponding physical devices. Details are not described herein again. 
     For example, the processor  2002  may be specifically the processor  110  shown in  FIG. 2 , the memory  2003  may be specifically the internal memory  121  and/or the external memory  120  shown in  FIG. 2 , and the display  2007  may be specifically the display  194  shown in  FIG. 2 , and the touch-sensitive surface  2006  may be specifically the touch sensor  180 K in the sensor module  180  shown in  FIG. 2 . This is not limited in the embodiments of this application. 
     The foregoing descriptions about implementations allow a person skilled in the art to understand that, for the purpose of convenient and brief description, division of the foregoing function modules is taken as an example for illustration. In actual application, the foregoing functions can be allocated to different modules and implemented according to a requirement, that is, an inner structure of an apparatus is divided into different function modules to implement all or some of the functions described above. For a detailed working process of the foregoing system, apparatus, and unit, refer to a corresponding process in the foregoing method embodiments, and details are not described herein again. 
     Function units in the embodiments of this application may be integrated into one processing unit, or each of the units may exist alone physically, or two or more units are integrated into one unit. The integrated unit may be implemented in a form of hardware, or may be implemented in a form of a software function unit. 
     When the integrated unit is implemented in the form of a software function unit and sold or used as an independent product, the integrated unit may be stored in a computer-readable storage medium. Based on such an understanding, the technical solutions of the embodiments of this application essentially, or the part contributing to the conventional technology, or all or some of the technical solutions may be implemented in the form of a software product. The computer software product is stored in a storage medium and includes several instructions for instructing a computer device (which may be a personal computer, a server, or a network device) or a processor to perform all or some of the steps of the methods described in the embodiments of this application. The foregoing storage medium includes: any medium that can store program code, such as a flash memory, a removable hard disk, a read-only memory, a random access memory, a magnetic disk, or an optical disc. 
     The foregoing descriptions are merely specific implementations of the embodiments of this application, but are not intended to limit the protection scope of the embodiments of this application. Any variation or replacement within the technical scope disclosed in the embodiments of this application shall fall within the protection scope of the embodiments of this application. Therefore, the protection scope of the embodiments of this application shall be subject to the protection scope of the claims.