为什么我的插座没有？ [英] Why is my outlet nil?

问题描述

我在使用可可项目时遇到问题。我显示一个键盘组成的NSButtons，我想，当我点击其中一个键，标签添加到NSTextField。我有一个控制器，我用作单例，所以每个键知道如何访问控制器。在控制器，我有一个出口链接到NSTextField。当我点击一个键，没有任何反应。所以我在mouseDown事件上使用了 NSLog（@％@，[[[OakController] sharedInstance] textarea]），在控制台输出， code>（null）。

I'm having trouble with a cocoa project. I'm displaying a keyboard composed of NSButtons, and I'd like that when I click on one of the keys, the label is added to a NSTextField. I have a controller that I use as a singleton, so each key "knows" how to access the controller. In the controller, I have an outlet linked to the NSTextField. When I click on a key, nothing happens. So I used something like NSLog(@"%@", [[[OakController] sharedInstance] textarea]) on a mouseDown event, and in the console output, I get (null).

很长的故事，我的插座设置为nil，我不知道为什么

Long story short, my outlet is set to nil, and I don't know why it is that way, or how to solve that...

以下是控制器的代码： https://gist.github.com/1090564 。

Here's the code of the controller : https://gist.github.com/1090564. Sorry for the lack of syntax coloring.

推荐答案

非常感谢您阅读。

我的猜测是，你实际上有多个实例的OakController，而不是一个像你所期望的。你把一个蓝色的多维数据集拖到你的IB文档，并将其自定义类更改为OakController？这将每次分配和初始化一个新的对象。我想你的sharedInstance方法也分配和初始化一个实例。

My guess is that you actually have multiple instances of OakController instead of one like you expect. Did you drag a blue cube into your IB document and change its custom class to OakController? That will allocate and initialize a new object each time. I'd guess that your sharedInstance method also allocates and initializes an instance.

尝试添加一个awakeFromNib方法到OakController，并添加一个断点。记录自我的指针值。在第二种情况下，插座意外地为nil，也记录自己的指针地址。

Try adding an awakeFromNib method to OakController, and add a break point. Log self's pointer value. In your second case were the outlet is unexpectedly nil, also log self's pointer address.

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