How to set Wallpaper Image programmatically in Android?

This example demonstrates how do I set Android Wallpaper image in Android.
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.
<LinearLayout 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:layout_width="wrap_content"
      android:layout_height="wrap_content"
      android:id="@+id/button"
      android:text="Set Wallpapaer"
      android:layout_gravity="center_vertical"
      android:layout_centerInParent="true"
      android:layout_marginLeft="135dp"/>
</LinearLayout>
Step 3 − Add the following code to src/MainActivity.java
import android.app.WallpaperManager;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.Toast;
import java.io.IOException;
public class MainActivity extends AppCompatActivity {
   @Override
   protected void onCreate(Bundle savedInstanceState) {
      super.onCreate(savedInstanceState);
      setContentView(R.layout.activity_main);
      Button button = (Button) findViewById(R.id.button);
      button.setOnClickListener(new View.OnClickListener() {
         @Override
         public void onClick(View v) {
            setWallpaper();
         }
      });
   }
   private void setWallpaper() {
      Bitmap bitmap = BitmapFactory.decodeResource(getResources(), R.drawable.wallpaper);
      WallpaperManager manager = WallpaperManager.getInstance(getApplicationContext());
      try{
         manager.setBitmap(bitmap);
         Toast.makeText(this, "Wallpaper set!", Toast.LENGTH_SHORT).show();
      } catch (IOException e) {
         Toast.makeText(this, "Error!", Toast.LENGTH_SHORT).show();
      }
   }
}
Step 4 − 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">
   <uses-permission android:name="android.permission.SET_WALLPAPER"/>
   <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 −
Click here to download the project code.