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); } }); } ```