How can I create custom button in Android using XML Styles?

This example demonstrates how do I create custom button in Android using XML Styles.
Step 1 − Create a new project in Android Studio, go to File ⇒ New Project and fill all required details to create a new project.
Step 2 − Add the following code to res/layout/activity_main.xml.
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
   xmlns:tools="http://schemas.android.com/tools"
   android:layout_width="match_parent"
   android:layout_height="match_parent"
   tools:context=".MainActivity">

   <Button
      android:id="@+id/customButton"
      android:layout_width="200dp"
      android:layout_height="wrap_content"
      android:layout_centerInParent="true"
      android:background="@drawable/custom_button"
      android:text="My Custom button"/>

   <Button
      android:id="@+id/customButton2"
      android:layout_width="200dp"
      android:layout_height="wrap_content"
      android:layout_centerInParent="true"
      android:layout_below="@id/customButton"
      android:layout_marginTop="24sp"
      android:background="@drawable/custom_button2"
      android:text="My Custom button"/>

   <Button
      android:id="@+id/customButton3"
      android:layout_width="200dp"
      android:layout_height="200dp"
      android:layout_centerInParent="true"
      android:layout_above="@id/customButton"
      android:layout_marginBottom="24sp"
      android:layout_marginTop="24sp"
      android:background="@drawable/custom_button3"
      android:text="My Custom button"/>
</RelativeLayout>
Step 3 – Right Click on res/drawable, Select new → Drawable resource file and add the following code in custom_dialog.xml
<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android"
   android:shape="rectangle">

   <stroke android:color="#66F9B9" android:width="4dp"/>
   <corners android:radius="16sp"/>
</shape>
Step 4 – Right Click on res/drawable, Select new → Drawable resource file and add the following code in custom_dialog2.xml
<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android"
   android:shape="rectangle">

   <gradient android:startColor="#2AF598" android:centerColor="#ff1493"
      android:endColor="@color/colorPrimary"/>
   <corners android:radius="50dp"/>
</shape>
Step 5 – Right Click on res/drawable, Select new → Drawable resource file and add the following code in custom_dialog3.xml
<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android"
   android:shape="rectangle">

   <solid android:color="#80121a" />
   <corners android:radius="999dp"/>
</shape>
Step 6 − Add the following code to src/MainActivity.java
package app.com.sample;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;

public class MainActivity extends AppCompatActivity {
   @Override
   protected void onCreate(Bundle savedInstanceState) {
      super.onCreate(savedInstanceState);
      setContentView(R.layout.activity_main);
   }
}
Step 7 - Add the following code to androidManifest.xml
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
   package="app.com.sample">

   <application
      android:allowBackup="true"
      android:icon="@mipmap/ic_launcher"
      android:label="@string/app_name"
      android:roundIcon="@mipmap/ic_launcher_round"
      android:supportsRtl="true"
      android:theme="@style/AppTheme">
      <activity android:name=".MainActivity">
         <intent-filter>
            <action android:name="android.intent.action.MAIN" />
            <category android:name="android.intent.category.LAUNCHER" />
         </intent-filter>
      </activity>
   </application>
</manifest>
Let's try to run your application. I assume you have connected your actual Android Mobile device with your computer. To run the app from android studio, open one of your project's activity files and click Run  Icon from the toolbar. Select your mobile device as an option and then check your mobile device which will display your default screen –