要为UITableViewController子类覆盖哪个初始化程序 [英] Which initializer(s) to override for UITableViewController subclass

问题描述

我有一个 UITableViewController 子类实例化，取决于它的使用，在NIB或通过代码。在这两种情况下，我想在initializer方法中进行自定义。这是否意味着我需要实现 initWithNibName：bundle： 和 initWithCoder：每个方法都会调用它各自的超级初始化器？

I have a UITableViewController subclass that's instantiated, depending on where it's used, in a NIB or via code. In both cases I want to do customization in the initializer method. Does that mean I need to implement both initWithNibName:bundle: and initWithCoder:, and would each method call its respective super initializer?

虽然我现在不需要这个，但如果我也想要能够实例化视图控制器 initWithStyle：？然后我需要3个不同的init方法来复制相同的行为吗？

While I don't need this right now, what if I also want to be able to instantiate the view controller with initWithStyle:? Would I then need 3 different init methods that replicate the same behavior?

看起来这违反了整个指定的初始化器约定，因为本质上有3个单独的初始化器最后调用一个公共的init方法。

It seems like this violates the whole designated initializer convention, as there would essentially be 3 separate initializers that don't end up calling a common init method. Or is there a way to create a common designated initializer while supporting the 3 different instantiate routes?

推荐答案

我的困惑是基于以下两个原因：错误地认为每个类应该有一个指定的初始化器。这不是真的，在 UITableViewController 的情况下有3个指定的初始化器（据我所知）：

My confusion was based on the mistaken belief that each class should have a single designated initializer. This is not true, and in the case of UITableViewController there are 3 designated initializers (as far as I can tell):

1. initWithStyle：本地声明


2. initWithNibName：bundle： code>继承自 UIViewController


3. initWithCoder： code> NSCoding 协议

1. initWithStyle: declared locally
2. initWithNibName:bundle: inherited from UIViewController
3. initWithCoder: from adopting NSCoding protocol

您需要覆盖1个 ，取决于您的子类实例化的方式。在我的情况下，我不得不实现＃2和＃3，因为类可以从NIB加载，或通过参考NIB的代码实例化。 （我想，对于单个类，你很少会使用 initWithStyle：和 initWithNibName：bundle：）。

You need to override 1 or more of these in your subclass depending on how your subclass gets instantiated. In my case I had to implement #2 and #3 since the class can be loaded from a NIB, or instantiated via code with reference to a NIB. (I imagine it's rare that you'll use both initWithStyle: and initWithNibName:bundle: for a single class.)

我发现苹果 Cocoa的编码指南 有用。

I found Apple's Coding Guidelines for Cocoa helpful.

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