How to create shadow in Android Buttons ?

•     Add the following code to res/layout/activity_main.xml.

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout
   xmlns:android="http://schemas.android.com/apk/res/android"
   xmlns:app="http://schemas.android.com/apk/res-auto"
   xmlns:tools="http://schemas.android.com/tools"
   android:layout_width="match_parent"
   android:layout_height="match_parent"
   tools:context=".MainActivity">
   <TextView
      android:layout_width="wrap_content"
      android:layout_height="wrap_content"
      android:text="Hello World!"
      app:layout_constraintBottom_toBottomOf="parent"
      app:layout_constraintLeft_toLeftOf="parent"
      app:layout_constraintRight_toRightOf="parent"
      app:layout_constraintTop_toTopOf="parent" />
   <Button
      android:layout_width="wrap_content"
      android:layout_height="wrap_content"
      android:layout_marginTop="20dp"
      android:width="200dp"
      android:layout_gravity="center"
      android:text="Shadow Button"
      android:background="@drawable/shadow_button_layer_list"/>
</androidx.constraintlayout.widget.ConstraintLayout>

•     Add the following code to src/MainActivity.java

package com.medkart.sample;
import androidx.appcompat.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);
   }
}

•     Add the following code to res/drawable/shadow_button_layer_list.xml

<?xml version="1.0" encoding="utf-8"?>
<layer-list xmlns:android="http://schemas.android.com/apk/res/android">
   <!-- Gray shadow. -->
   <item android:left="3dp" android:top="5dp">
      <shape>
         <solid android:color="@android:color/darker_gray" />
         <corners android:radius="15dp" />
      </shape>
   </item>
   <!-- White foreground. -->
   <item android:bottom="5dp" android:right="3dp">
      <shape>
         <solid android:color="@android:color/white" />
         <corners android:radius="15dp" />
      </shape>
   </item>
</layer-list>

•     Add the following code to Manifests/AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
   package="com.medkart.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>

OutPut