设置背景然后膨胀布局

Question

我想要扩展要查看的布局，然后将其添加到WindowManager，但在我想让布局的背景与墙纸相同之前。我已经尝试过这段代码，但遗憾的是WindowManager没有显示我的新背景。请帮助我!!! 我的代码：

final WallpaperManager wallpaperManager = WallpaperManager.getInstance(this);
        final Drawable wallpaperDrawable = wallpaperManager.getDrawable();
RelativeLayout rl = (RelativeLayout) findViewById(R.id.main);
rl.setBackgroundDrawable(wallpaperDrawable); 
final WindowManager.LayoutParams params = new WindowManager.LayoutParams(
            WindowManager.LayoutParams.TYPE_SYSTEM_OVERLAY,
            WindowManager.LayoutParams.FLAG_LAYOUT_IN_SCREEN |
                    WindowManager.LayoutParams.FLAG_LAYOUT_NO_LIMITS |
                    WindowManager.LayoutParams.FLAG_NOT_TOUCHABLE |
                    WindowManager.LayoutParams.FLAG_NOT_FOCUSABLE,
            PixelFormat.TRANSLUCENT);

    WindowManager wm = (WindowManager) getApplicationContext()
            .getSystemService(Context.WINDOW_SERVICE);
    LayoutInflater inflater = (LayoutInflater) this.getSystemService
            (Context.LAYOUT_INFLATER_SERVICE);
    ViewGroup mTopView = (ViewGroup) inflater.inflate(R.layout.activity_main, null, true);
    getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN, WindowManager.LayoutParams.FLAG_FULLSCREEN);
    getWindow().setAttributes(params);
    wm.addView(mTopView, params);