我有一个位图,我想从该位图裁剪一个圆形区域。圆外的所有像素均应透明。我怎样才能做到这一点?
经过长时间的头脑风暴,我找到了解决方案
public Bitmap getCroppedBitmap(Bitmap bitmap) { Bitmap output = Bitmap.createBitmap(bitmap.getWidth(), bitmap.getHeight(), Config.ARGB_8888); Canvas canvas = new Canvas(output); final int color = 0xff424242; final Paint paint = new Paint(); final Rect rect = new Rect(0, 0, bitmap.getWidth(), bitmap.getHeight()); paint.setAntiAlias(true); canvas.drawARGB(0, 0, 0, 0); paint.setColor(color); // canvas.drawRoundRect(rectF, roundPx, roundPx, paint); canvas.drawCircle(bitmap.getWidth() / 2, bitmap.getHeight() / 2, bitmap.getWidth() / 2, paint); paint.setXfermode(new PorterDuffXfermode(Mode.SRC_IN)); canvas.drawBitmap(bitmap, rect, rect, paint); //Bitmap _bmp = Bitmap.createScaledBitmap(output, 60, 60, false); //return _bmp; return output; }