圆角图片最简单实现方式

重写iamgeview 的下边两个方法，轻松实现任意圆角
` @Override
public void setImageDrawable(@Nullable Drawable drawable) {
if (drawable != null && drawable instanceof BitmapDrawable) {
Bitmap bitmap = ((BitmapDrawable) drawable).getBitmap();
setImageBitmap(bitmap);
} else {
super.setImageDrawable(drawable);
}
}

@Override public void setImageBitmap(Bitmap bm) {
    //super.setImageBitmap(bm);
    RoundedBitmapDrawable drawable = RoundedBitmapDrawableFactory.create(
            getResources(), bm);
    drawable.setCornerRadius(36);
    setImageDrawable(drawable);
}`