ClassCastException：BitmapDrawable 无法转换为 LayerDrawable

【问题标题】：ClassCastException: BitmapDrawable cannot be cast to LayerDrawableClassCastException：BitmapDrawable 无法转换为 LayerDrawable
【发布时间】：2016-05-04 02:40:33
【问题描述】：

我想在操作栏中添加徽章计数器并使其也可点击

    getMenuInflater().inflate(R.menu.main_menu, menu);
    MenuItem item = menu.findItem(R.id.action_notifications);
    LayerDrawable icon = (LayerDrawable) item.getIcon();
    Utils2.setBadgeCount(this, icon, 2);
    return true;

错误：

java.lang.ClassCastException: android.graphics.drawable.BitmapDrawable cannot be cast to android.graphics.drawable.LayerDrawable

【问题讨论】：

stackoverflow.com/questions/15805060/…
如果我可以这个线程解决相反的问题，从 LayerDrawable 转换为 BitmapDrawable

标签： java android casting

【解决方案1】：

正如@IntelliJ 所说，这已经是answered：

public Drawable geSingleDrawable(LayerDrawable layerDrawable){

      int resourceBitmapHeight = 136, resourceBitmapWidth = 153;

      float widthInInches = 0.9f;

      int widthInPixels = (int)(widthInInches * getResources().getDisplayMetrics().densityDpi);
      int heightInPixels = (int)(widthInPixels * resourceBitmapHeight / resourceBitmapWidth);

      int insetLeft = 10, insetTop = 10, insetRight = 10, insetBottom = 10;

      layerDrawable.setLayerInset(1, insetLeft, insetTop, insetRight, insetBottom);     

      Bitmap bitmap = Bitmap.createBitmap(widthInPixels, heightInPixels, Bitmap.Config.ARGB_8888);

      Canvas canvas = new Canvas(bitmap);
      layerDrawable.setBounds(0, 0, widthInPixels, heightInPixels);
      layerDrawable.draw(canvas);

      BitmapDrawable bitmapDrawable = new BitmapDrawable(getResources(), bitmap);
      bitmapDrawable.setBounds(0, 0, widthInPixels, heightInPixels);

      return bitmapDrawable;
}

【讨论】：