Android-Service实现手机壁纸自动更换

<service android:name=\".ChangeService\"></service>

public class ChangeService extends Service {
  int[] wallpapers = new int[]{
      R.drawable.a2, R.drawable.a3, R.drawable.a4
  };
  WallpaperManager wallpaperManager;
  int current = 0;
  @Override
  public void onCreate() {
    super.onCreate();
    wallpaperManager = WallpaperManager.getInstance(this);
  }
  @Override
  public int  Command(Intent intent, int flags, int startId) {
    if (current >= 3) {
      current = 0;
    } try {
      wallpaperManager.setResource(wallpapers[current++]);
    } catch (IOException e) {
      e.printStackTrace();
    } return START_STICKY;
  }
  @Nullable
  @Override
  public IBinder onBind(Intent intent) {
    return null;
  }
}

public class MainActivity extends Activity {
  private Button mStart;
  private Button mStop;

  @Override
  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    mStart = (Button) findViewById(R.id.start);
    mStop = (Button) findViewById(R.id.stop);

    final Intent intent = new Intent(MainActivity.this, ChangeService.class);
     final PendingIntent pi = PendingIntent.getService(MainActivity.this, 0, intent, 0);
     mStart.set Listener(new View. Listener() {
       @Override
       public void  (View v) {
         AlarmManager alarmManager = (AlarmManager) getSystemService(Service.ALARM_SERVICE);
         alarmManager.setRepeating(AlarmManager.ELAPSED_REALTIME_WAKEUP, 0, 2000, pi);
         mStart.setEnabled(false); mStop.setEnabled(true);
         Toast.makeText(MainActivity.this, \"壁纸定时更换启动成功啦\", Toast.LENGTH_SHORT).show();
       }
     });
     mStop.set Listener(new View. Listener() {
       @Override public void  (View v) {
         mStart.setEnabled(true);
       mStop.setEnabled(false);

       AlarmManager alarmManager = (AlarmManager) getSystemService(Service.ALARM_SERVICE);
        alarmManager.cancel(pi);
       }
     });
  }
}

<?  version=\"1.0\" encoding=\"utf-8\"?>
<RelativeLayout
   ns:android=\"http://schemas.android.com/apk/res/android\"
   ns:tools=\"http://schemas.android.com/tools\"
  android:layout_width=\"match_parent\"
  android:layout_height=\"match_parent\"
  android:orientation=\"vertical\" >

  <LinearLayout
    android:layout_width=\"match_parent\"
    android:layout_height=\"wrap_content\"
    android:layout_alignParentBottom=\"true\"
    android:orientation=\"horizontal\">

    <Button
      android:id=\"@+id/start\"
      android:layout_width=\"wrap_content\"
      android:layout_height=\"wrap_content\"
      android:layout_weight=\"1\"
      android:gravity=\"center_horizontal\"
      android:text=\"Start\"
      android:textSize=\"25dp\"
      android:textColor=\"#ffffffff\"/>

    <Button
      android:id=\"@+id/stop\"
      android:layout_width=\"wrap_content\"
      android:layout_height=\"wrap_content\"
      android:layout_weight=\"1\"
      android:gravity=\"center_horizontal\"
      android:text=\"Stop\"
      android:textSize=\"25dp\"
      android:textColor=\"#ffffffff\"/>
  </LinearLayout>

</RelativeLayout>