android 图片处理之制作圆角图片

处理圆角图片关键就在于使用 Paint的setXfermode

相关资料：http://blog.csdn.net/wm111/article/details/7299294

以下是改进一个前人做的圆角图片的例子，少创建一次bitmap

public static Bitmap roundCorners(final Bitmap source, final float radius) {

int width = source.getWidth();
int height = source.getHeight();

Paint paint = new Paint();
paint.setAntiAlias(true);
paint.setColor(android.graphics.Color.WHITE);

Bitmap clipped = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888);
Canvas canvas = new Canvas(clipped);
canvas.drawRoundRect(new RectF(0, 0, width, height), radius, radius,
paint);

paint.setXfermode(new PorterDuffXfermode(android.graphics.PorterDuff.Mode.SRC_IN));
canvas.drawBitmap(source, 0, 0, paint);

source.recycle();

return clipped;

}

原例：

                                                                                                                                                            }