overlapping gesture recognizer on UIImageView

Question

I have multiple UIImageView added into the main view, each UiImageView is displayed in its own parent UIView for cropping purpose and each UIImageView is also attached to a PanGestureRecognizer. I am curious on how to implement both pan gesturerecgonizer and also allow image swap by dragging one image (A) to hover over the other image (B) and hold, then the image A and B will be swapped (so A is now displayed in old B's UIView).. this is something like the iphoto app just implemented.

my thought would be somehow create a custom gesture recognizer at the superview layer, but I don't want to lose the pangesturerecognizer applied to each image, how can this be done?

Answer 1

为什么不通过两个手指来启用平移手势，而通过touches方法来实现拖动功能呢？