问题
I write this link's answer code to create ImageViewLayer and Imageview. StackOverflow Link
This link gives me the below result.
It's work fine .But I want ,when user press the original button... and then touches with finger it remove the clear area ang fill with the previous one.
And how to create Undo Functionality for this..If any question regarding this please add your comment..Please help me...
回答1:
how to draw CALayer with line path like simulate eraser effect?
this is the post i get the answer. there is a sample code about the effect. what you are different is change the gray color layer to be the "paper imager"
hope it help you
来源：https://stackoverflow.com/questions/27438068/draw-and-erase-on-imageview-using-uibezierpath