objective-c - Should an outlet to a view controller class be weak or stong? OSX app

Question

Here's what i did.

1. Make a clean OSX project.
2. went to main.xib and dragged a popover controller. This created 2 visible objects on on interface builder.

3. I went to the appDelegate.h file and did

   `-@Property (assign) IBOutlet NSViewController *popVC;

4. Then i went to the applicationDidFinishLaunching: method and did

   popVC = [[NSViewController alloc] init];

Result: I get the following error message:

Shouldnt objects on a nib be weak since it is already owned by the nib?

Answer 1

查看控制器的插座应该是strong. NIB 不拥有这些对象，它只是一个档案。视图的出口通常应该是weak，但这是因为视图由其超级视图保留（超级视图通常由其视图控制器保留）。

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顺便说一句，你不应该这样做：

popVC = [[NSViewController alloc] init];

因为popVC在加载 NIB 时正在取消归档、创建和设置。通过自己创建和设置实例，您将丢弃 NIB 版本。这适用于所有插座 - 加载 NIB 时我要填写的插座的目的。