iOS - UITextView + NSUndoManager [英] iOS - UITextView + NSUndoManager

问题描述

我试图在UITextView（我正在构建一个LateX编辑器）没有运气，并且老实说，我真的很困惑这个论点的整合撤消/重做功能。我不明白这两个操作涉及的步骤，我的意思是我需要两个方法

I'm trying to integrate the undo/redo features in a UITextView (I'm building a LateX editor) with no luck and to be honest I'm really confused about this argument. I don't understand the steps involved in those two operations, I mean I need two methods

• 一个删除最后插入的文本
• 
  
• 一个恢复删除的文本

一个疑问是我得到最后插入的文本？换句话说，我必须注册撤消？

One doubt is where I get the last inserted text? in other words where I have to register for the undo?

• 在textViewDidChange中我可以得到整个文本


• 在textViewShouldChangeTextInRange中，

我知道我写的不是最好的解释，但我希望有人在这里曾经遇到过同样的问题并可以给我一个提示。基本上，为了恢复，我必须添加撤消/重做功能到一个textview，可能有两个按钮链接到这些动作。

I know that what I wrote wasn't the best explanation ever, But I hope someone here has faced the same problem in the past and can give me an hint. Basically ,to resume, I have to add the undo/redo features to a textview, possibly having two buttons linked with those actions.

提前感谢

推荐答案

我现在感觉像一个白痴（解决方案真的很容易... textView已经有一个undoManager所以基本上步骤有一个textView的撤销/重做操作是：
在viewDidload内：

I'm feeling like an idiot right now :( the solution was really really easy... The textView has already an undoManager so basically the steps to have undo/redo actions for a textView are : inside viewDidload :

myUndoManager = [textView undoManager];

您要执行操作的位置

[myUndoManager undo]; // or redo

真的哑的有时，我几乎写我自己的撤销代码...我希望这可以帮助某人

I'm really dumb sometimes, I was almost writing my own undo code... I hope this can help someone

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