objective-c - cocoa 爷爷

Question

是否可以访问对象父类(super class)(或祖父)的父类(super class)方法？

例如:

GrandFatherObject : NSObject
SuperObject : GrandFatherObject
SelfObject : SuperObject

来自 SelfObject:

- (void)overriddenMethod
{
  // For Self
  someCode();

  // For Parent
  [super overriddenMethod];

  // For GrandParent
  ???
}

我只能访问 SelfObject(不能修改 SuperObject 或 GrandFatherObject)

Answer 1

是的，你可以做到，但它比仅仅调用 super 需要更多的代码。

或多或少，它会是这样的:

#import <objc/runtime.h>

struct objc_super grandsuper;
grandsuper.receiver = self;
grandsuper.class = class_getSuperclass(class_getSuperclass([self class]));

//if _cmd has a non-struct return value:
id grandsuperReturnValue = objc_msgSendSuper(&grandsuper, _cmd, arg1, arg2, ...);