How can I replace text in UITextView with NSUndoManager support?

Question

I want to be able to replace some text in an UITextView programatically, so I wrote this method as an UITextView category:

- (void) replaceCharactersInRange:(NSR         


        

Answer 1

I've been having trouble with this for a long time. I finally realized that you have to make sure you register the undo operation BEFORE doing any changes to your text storage.