Android使用线程更换壁纸

public class MainActivity extends Activity {
  Thread thread = new Thread(){
    @Override
    public void run() {
      for (;current<5;){
        if (current  = 3) {
          current = 0;
        }
        //使用资源文件 当然你也可以使用其他图片bitmap
        BitmapDrawable bitmap = (BitmapDrawable) getResources().getDrawable(wallpapers[current++]);
        wallpaperManager = WallpaperManager.getInstance(MainActivity.this);
        try {
          wallpaperManager.setBitmap(bitmap.getBitmap());
        } catch (IOException e) {
          e.printStackTrace();
        }
      }
    }
  };
  int[] wallpapers = new int[]{
      R.drawable.background1, R.drawable.background2, R.drawable.background3
  };
  WallpaperManager wallpaperManager;
  int current = 0;
  @Override
  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    thread.start();
  }
}

<!--授予用户修改壁纸权限-- 
  <uses-permission android:name="android.permission.SET_WALLPAPER" /