Android setOutlineProvider 设置阴影

if (Build.VERSION.SDK_INT >= 21) {
    view.setElevation(10);
    view.setClipToOutline(true);
    view.setOutlineProvider(new ViewOutlineProvider() {
           @Override
           public void getOutline(View view, Outline outline) {
               outline.setRoundRect(0, 0, view.getWidth(), view.getHeight(), radius);
           }
       });
    }