Java android删除矩形并绘制其余图像

Question

I am trying to crop a rectangle from a bitmap and draw the rest of the image on a canvas.Could achieve that so far.Could you please help? Code is as below-

1. //draw activity on the canvas. this returns a bitmap used in Bitmap.createBitmap(3)
 activity.getWindow().getDecorView().draw(canvas);

2. //get the coordinates that I want to clip.
 Rect removeImage = new rect(coordinates of rect portion)

3. //check that I can get the cropped image 
Bitmap croppedImage = Bitmap.createBitmap(bitmap, leftCrop, topCrop,    rightCrop, bottomCrop);

4. //Now I want to get the remaining canvas and remove the rectangular region 
?????????

Answer 1

In order to remove a rectangular portion from the bitmap of an activity we can use following code-

    Bitmap bitmap = Bitmap.createBitmap(view.getWidth(), view.getHeight(), ARGB_8888);        
    Canvas canvas = new Canvas(bitmap);
    Paint p = new Paint();
    p.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.DARKEN));
    activity.getWindow().getDecorView().draw(canvas);
    canvas.drawRect(rect,p);
    canvas.save();

You can manually calculate the rectangle coordinates or supply yours. I passed the view and used the following -

    Rect coordinates = new Rect();
    int[] xyLocation = new int[2];
    if (view == null) {
        return coordinates;
    }
    view.getLocationOnScreen(xyLocation);
    coordinates.left = xyLocation[0];
    coordinates.top = xyLocation[1];
    coordinates.right = coordinates.left + view.getWidth();
    coordinates.bottom = corrdinates.top + view.getHeight();
    return coordinates;