为什么这段代码会给我一个关于弱属性的错误？
这是我在 iOS 上使用 ARC 编写的简单代码：
@interface Person : NSObject {
NSObject *objStrong;
NSObject *objWeek;
}
@property(strong) NSObject *objStrong;
//getting error at this line
@property(weak) NSObject *objWeek; //Existing ivar 'objWeek' for _week property 'objWeek' must be _week
@end
@implementation Person
@synthesize objStrong;
@synthesize objWeek;
@end
当我尝试编译时，编译器抱怨 _weak 属性“objWeek”的现有 ivar“objWeek”。为什么这段代码不能正确编译？
This is my simple piece of code on iOS, using ARC:
@interface Person : NSObject {
NSObject *objStrong;
NSObject *objWeek;
}
@property(strong) NSObject *objStrong;
//getting error at this line
@property(weak) NSObject *objWeek; //Existing ivar 'objWeek' for _week property 'objWeek' must be _week
@end
@implementation Person
@synthesize objStrong;
@synthesize objWeek;
@end
When I try to compile, the compiler complains about an existing ivar 'objWeek' for _weak property 'objWeek'. Why isn't this code compiling correctly?
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它会抱怨，因为支持变量
NSObject *objWeek被声明为__strong（所有其他未注释的指向可保留对象的 Objective C 指针都是__strong）。将支持变量更改为 __weak NSObject *objWeek，编译器将再次喜欢您。编辑：根据要求，来自 LLVM clang 的 ARC 文档：
链接：http://clang.llvm.org/docs/AutomaticReferenceCounting.html#ownership.inference
It's complaining because the backing variable,
NSObject *objWeekis declared as__strong(all otherwise unannotated Objective C pointers to retainable objects are__strong). Change the backing variable to be__weak NSObject *objWeek, and the compiler will like you again.Edit: As requested, the ARC documentation from LLVM's clang:
Link: http://clang.llvm.org/docs/AutomaticReferenceCounting.html#ownership.inference
我也遇到过同样的问题。我确实花了很多时间在这上面，最后我可以通过清理项目来解决这个问题。这就是方法....
product->clean
原因是你可能被删除了控制器类(ViewController)，但它仍然没有被删除从您的项目中删除。当您完成项目清理后，错误将自动消失。这对我有用......
Same problem I have faced. I did spend lot of time on this finally I could solve this problem by cleaning the project.Here is the way....
product->clean
The reason is you may be deleted controller class(ViewController) but still it is not removed from your project.when you finish cleaning of your project the error will be gone automatically. This worked for me...