Android：缩放背景ImageView后的对象（ImageView）重新定位

Question

在我的应用程序中，我想编写一个应用程序，当我在后台ImageView中缩放和移动时。然后，黑色的Imageview也将缩放并重新定位到相应的位置。例如，如果我将图像视图放在（100,100）（中心位置或您可以认为bg上有标记），那么在缩放bg后，图像视图仍然保留在此标记上。该动作如图1所示。对于＆＃34;移动＆＃34;，它对我来说非常适合。但是，对于像红色箭头一样的多指触摸，它会移动到错误的位置（缩放是正确的）...... 这是我用两个手指触摸缩放bg的代码，

MainActivity ：

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    imageView = (ImageView) findViewById(R.id.result);
    Bitmap myBitmap = BitmapFactory.decodeResource(getResources(), R.drawable.bg);
    ImageView ca = new ImageView(this);
    imageView.setImageBitmap(myBitmap);
    imageView.setOnTouchListener(new OnTouchListener() {

        @Override
        public boolean onTouch(View v, MotionEvent event) {
            view = (ImageView) v;
            view.setScaleType(ImageView.ScaleType.MATRIX);

            switch (event.getAction() & MotionEvent.ACTION_MASK) {
                case MotionEvent.ACTION_DOWN:  
                     matrix.set(view.getImageMatrix());
                     savedMatrix.set(matrix);
                     LayoutParams aaa = (LayoutParams) ca.getLayoutParams();
                     start.set(event.getX(), event.getY());
                     mode = DRAG;
                     break;
                case MotionEvent.ACTION_UP: // first finger lifted
                    move_x = event.getX()-start.x;
                    move_y = event.getY()-start.y;
                    float[] pts = {0.0f,0.0f};
                    Matrix m_image = imageView.getImageMatrix();
                    m_image.mapPoints(pts);
                    laststop.x = pts[0];
                    laststop.y = pts[1];
                    if (mode == DRAG) { 
                            LayoutParams aaaa = (LayoutParams) ca.getLayoutParams();    
                            int caLeft = aaaa.leftMargin;
                            int caTop = aaaa.topMargin;
                            aaaa.leftMargin = caLeft + (int)(move_x);
                            aaaa.topMargin  = caTop  + (int)(move_y);
                            ca.setLayoutParams(aaaa);
                            ca.invalidate();
                    }
                    mode = NONE;
                break;
                case MotionEvent.ACTION_POINTER_UP: // second finger lifted
                    if (mode == ZOOM){
                        scale_new = scale * scale_new;
                        if(ca != null && ca.freeze == true){
                            LayoutParams aa = (LayoutParams) ca.getLayoutParams();
                            int width_ori = aa.width;
                            int height_ori = aa.height;
                            int center_x = aa.leftMargin + width_ori/2;
                            int center_y = aa.topMargin  + height_ori/2;

                            aa.width = (int) (width_ori * scale);
                            aa.height = (int) (height_ori * scale);

                            aa.leftMargin = (int) ((center_x - aa.width/2)/scale);
                            aa.topMargin = (int) ((center_y - aa.height/2)/scale);

                            ca.setLayoutParams(aa);
                            ca.invalidate();
                        }
                    }

                            mode = NONE;
                            break;

                case MotionEvent.ACTION_POINTER_DOWN: 
                     oldDist = spacing(event);
                     if (oldDist > 5f) {
                        savedMatrix.set(matrix);
                        midPoint(mid, event);
                        mode = ZOOM;
                     }
                          break;
                case MotionEvent.ACTION_MOVE:
                    if (mode == DRAG) { 
                        matrix.set(savedMatrix);
                        matrix.postTranslate(event.getX() - start.x, event.getY() - start.y); 

                    } else if (mode == ZOOM) { 
                        newDist = spacing(event);
                        if (newDist > 5f) {
                                  matrix.set(savedMatrix);
                                  scale = newDist / oldDist; 
                                  matrix.postScale(scale, scale, mid.x, mid.y);
                        }
                    }
                break;
            }
            view.setImageMatrix(matrix); 
            return true;
        }
    });
}

图。 1