android 圖片處理之制作圓角圖片

 　　以下是改進一個前人做的圓角圖片的例子，少創建一次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：

　　/**

　　* Round the corners of a {@link Bitmap}

　　*

　　* @param source

　　* @param radius

　　* @return rounded corner 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(WHITE);

　　Bitmap clipped = Bitmap.createBitmap(width, height, ARGB_8888);

　　Canvas canvas = new Canvas(clipped);

　　canvas.drawRoundRect(new RectF(0, 0, width, height), radius, radius,

　　paint);

　　paint.setXfermode(new PorterDuffXfermode(DST_IN));

　　Bitmap rounded = Bitmap.createBitmap(width, height, ARGB_8888);

　　canvas = new Canvas(rounded);

　　canvas.drawBitmap(source, 0, 0, null);

　　canvas.drawBitmap(clipped, 0, 0, paint);

　　source.recycle();

　　clipped.recycle();

　　return rounded;

　　}