Objective-C 初始化(静态方法)调用了不止一次？

Question

我在 Objective-C 中有类似的代码:

SubclassOfNSObject *GlobalVariableThatShouldNeverChange;

@implementation MyClass

+(void) initialize
{
    [super initialize];
    GlobalVariableThatShouldNeverChange = [[SubclassOfNSObject alloc] init];
    // Change more stuff with GlobalVariableThatShouldNeverChange
}

@end

我在整个代码中都引用了 this，并且指向 this 的指针永远不会改变，因为我在我的代码中到处都在使用它。问题是，当我使用 GHUnit 运行测试时，我遇到了奇怪的问题，因为 GlobalVariableThatShouldNeverChange 的指针被更改(即它正在重新初始化。我有一个问题变量通过自动释放池释放并且已修复，我有解决此问题的方法，但我想知道为什么？

谢谢!

Answer 1

docs说:

The runtime sends initialize to each class in a program exactly one time just before the class, or any class that inherits from it.

推荐的方法是:

+ (void)initialize
{
    if (self == [GHUnit class]) {

        /* put initialization code here */

    }
}

另请注意文档中的以下建议:

… you should typically not send initialize to super in your implementation.