绘制图形时，通过绘制相交的部分来实现，不多说，看代码：
public static Bitmap getRoundedCornerBitmap(Bitmap sourceBitmap, float roundX, float roundY) {
try {
Bitmap targetBitmap = Bitmap.createBitmap(sourceBitmap.getWidth(), sourceBitmap.getHeight(), Config.ARGB_8888);
Canvas canvas = new Canvas(targetBitmap);
Paint paint = new Paint();
Rect rect = new Rect(0, 0, sourceBitmap.getWidth(), sourceBitmap.getHeight());
RectF rectF = new RectF(rect);
paint.setAntiAlias(true);
canvas.drawARGB(0, 0, 0, 0);
canvas.drawRoundRect(rectF, roundX, roundY, paint);
paint.setXfermode(new PorterDuffXfermode(Mode.SRC_IN));
canvas.drawBitmap(sourceBitmap, rect, rect, paint);
return targetBitmap;
} catch (Exception e) {
e.printStackTrace();
}
return null;
}
效果图：
