iOS UITableView:"cellForRowAtIndexPath"和"cellForRowAtIndexPath"之间有什么区别?和"willDisplayCell:forRowAtIndexPath:"； [英] iOS UITableView: what's the different between "cellForRowAtIndexPath" and "willDisplayCell: forRowAtIndexPath:"

问题描述

就像问题的标题提到的那样:

Just as the question's title mentions: What's the difference between "cellForRowAtIndexPath" and "willDisplayCell: forRowAtIndexPath:"?`

我认为可以在cellForRowAtIndexPath或willDisplayCell: forRowAtIndexPath:中完成单元配置！

I think cell configuration can be done either in cellForRowAtIndexPath or willDisplayCell: forRowAtIndexPath:"!

推荐答案

是的，在两种方法中都可以完成单元格配置(理论上).

You are right, cell configuration can (in theory) be done in both methods.

但是，几乎所有UITableView都有一个实现cellForRowAtIndexPath:的数据源(这是协议中的必需方法).另一方面，willDisplayCell:forRowAtIndexPath:(这是 delegate 的方法，而不是数据源)是可选的.

However, almost all UITableView have a data source which implements cellForRowAtIndexPath: (it is a required method in the protocol). On the other hand, the willDisplayCell:forRowAtIndexPath: (which is a method of the delegate, not the data source) is optional.

由于配置单元通常取决于您要显示的数据，因此cellForRowAtIndexPath:是迄今为止最常见的单元配置场所. (我什至不记得使用willDisplayCell:forRowAtIndexPath:).

As configuring a cell is usually dependent on the data you want to show, cellForRowAtIndexPath: is by far the most common place to do cell configuration. (I can't even remember using willDisplayCell:forRowAtIndexPath:).

有一个显着的例外:使用情节提要和静态单元格(而不是单元格原型)时，在cellForRowAtIndexPath:中无法做任何有用的事情(因为dequeueReusableCellWithIdentifier:返回nil)，因此您必须使用willDisplayCell:forRowAtIndexPath:，viewWillAppear:或其他方法进行配置.

There's one notable exception: when you are using a storyboard and static cells (instead of cell prototypes), you can't do anything useful in cellForRowAtIndexPath: (because dequeueReusableCellWithIdentifier: returns nil), so you have to do configuration in willDisplayCell:forRowAtIndexPath:, viewWillAppear: or other methods.

@NSDeveloper:您是对的.感谢您的提示.

@NSDeveloper: you're right. Thanks for the hint.

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