Android 图片圆角

/**
     * 将图片转化为圆角图片
     * 
     * @param drawable
     * @param roundPX
     * @return
     */
    private static Bitmap getRoundCornerDrawable(Drawable drawable, float roundPX /* 圆角的半径 */) {
        int w = drawable.getIntrinsicWidth();
        int h = drawable.getIntrinsicHeight();

        Bitmap bitmap = Bitmap.createBitmap(w, h, drawable.getOpacity() != PixelFormat.OPAQUE ? Bitmap.Config.ARGB_8888
                : Bitmap.Config.RGB_565);

        Canvas canvas = new Canvas(bitmap);
        drawable.setBounds(0, 0, w, h);
        drawable.draw(canvas);

        int width = bitmap.getWidth();
        int height = bitmap.getHeight();
        Bitmap retBmp = Bitmap.createBitmap(width, height, Config.ARGB_8888);
        Canvas can = new Canvas(retBmp);

        final int color = 0xff424242;
        final Paint paint = new Paint();
        final Rect rect = new Rect(0, 0, width, height);
        final RectF rectF = new RectF(rect);

        paint.setColor(color);
        paint.setAntiAlias(true);
        can.drawARGB(0, 0, 0, 0);
        can.drawRoundRect(rectF, roundPX, roundPX, paint);

        paint.setXfermode(new PorterDuffXfermode(Mode.SRC_IN));
        can.drawBitmap(bitmap, rect, rect, paint);
        // return new BitmapDrawable(retBmp);
        return retBmp;
    }