地址簿常量评估为零 [英] Address Book constants evaluating as zero

问题描述

我有一个程序，对于某些代码路径，地址簿常量（例如kABPersonEmailProperty，kABPersonAddressProperty）评估为其正常的非零值。但是，如果我遵循不同的代码路径，所有这些常量都会计算为零。

I have a program where for certain code paths, the address book constants (such as kABPersonEmailProperty, kABPersonAddressProperty) evaluate to their normal non-zero value. However, if I follow a different code path, all these constants evaluate to zero.

此外，一旦我按照成功的代码路径，如果我采用有问题的代码它运作的路径。

Furthermore, once I follow the "successful" code path, if I take the problematic code path it works.

这是某种编译链接问题吗？

Is this some kind of compile linkage issue ?

我也可能过度释放某个变量。

I could also be over-releasing a variable somewhere.

推荐答案

好的，神秘的解决了。以Apple为荣，记录了这种行为。

Okay, mystery solved. To Apple's credit, the behavior is documented.

参见链接文本

特殊注意事项：这些常量的值未定义，直到其中一个以下内容被称为：ABAddressBookCreate，ABPersonCreate，ABGroupCreate。

"Special Considerations: The value of these constants is undefined until one of the following has been called: ABAddressBookCreate, ABPersonCreate, ABGroupCreate."

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