请确保u必须在AndroidManifest文件的权限：

Make Sure u have the permission in AndroidManifest File :

  <uses-permission android:name="android.permission.RECEIVE_BOOT_COMPLETED" />

更改为：

@Override
public void onReceive(Context context, Intent intent) {
    Intent serviceIntent = new Intent(context,BackgroundService.class);
    startService(serviceIntent);
    }