A portable device, comprising: a camera unit having a plurality of functional modes, the functional modes comprising a photo-capturing mode and a video-recording mode; a first sensor, disposed on the portable device and configured for sensing a manipulation input, the manipulation input having a manipulation pattern and duration information of the manipulation pattern, wherein the first sensor is a switch button; a control module, coupled with the camera unit and the first sensor, the control module being configured for selecting one of the functional modes corresponding to the manipulation pattern and press and hold duration information sensed by the first sensor, and triggering the camera unit into the selected functional mode, wherein in response to the manipulation pattern of the switch button comprising the switch button is pressed and then released within a first predetermined duration, the photo-capturing mode is selected by the control module, and the camera unit is triggered to capture one photo at the time instant of pressing or releasing the switch button, wherein in response to a manipulation pattern of the switch button comprising the switch button is pressed and held over the first predetermined duration, the video-recording mode is selected by the control module, and the camera unit is triggered to start capturing a video at the end of the first predetermined duration, the portable device being characterised in that in response to the switch button being released within a second predetermined period after pressing and holding the switch button over a first predetermined duration for selecting the video-recoding mode, the camera unit is triggered to stop the video-recording mode, the first and second predetermined period being initiated at the same time instant and the second predetermined duration being longer than the first predetermined duration; and in response to the manipulation pattern of the switch button comprising: the switch button is pressed, held over the first predetermined duration and released after the second predetermined duration, the camera unit is locked in the video-recording mode by the control module until the switch button is pressed again and then released within a first predetermined duration. a camera unit having a plurality of functional modes, the functional modes comprising a photo-capturing mode and a video-recording mode; a first sensor, disposed on the portable device and configured for sensing a manipulation input, the manipulation input having a manipulation pattern and duration information of the manipulation pattern, wherein the first sensor is a switch button; a control module, coupled with the camera unit and the first sensor, the control module being configured for selecting one of the functional modes corresponding to the manipulation pattern and press and hold duration information sensed by the first sensor, and triggering the camera unit into the selected functional mode, wherein in response to the manipulation pattern of the switch button comprising the switch button is pressed and then released within a first predetermined duration, the photo-capturing mode is selected by the control module, and the camera unit is triggered to capture one photo at the time instant of pressing or releasing the switch button, wherein in response to a manipulation pattern of the switch button comprising the switch button is pressed and held over the first predetermined duration, the video-recording mode is selected by the control module, and the camera unit is triggered to start capturing a video at the end of the first predetermined duration, the portable device being characterised in that in response to the switch button being released within a second predetermined period after pressing and holding the switch button over a first predetermined duration for selecting the video-recoding mode, the camera unit is triggered to stop the video-recording mode, the first and second predetermined period being initiated at the same time instant and the second predetermined duration being longer than the first predetermined duration; and in response to the manipulation pattern of the switch button comprising: the switch button is pressed, held over the first predetermined duration and released after the second predetermined duration, the camera unit is locked in the video-recording mode by the control module until the switch button is pressed again and then released within a first predetermined duration.