你如何从其他地方调用Objective-C对象的超类的方法？ [英] How do you call a method for an Objective-C object's superclass from elsewhere?

问题描述

如果你正在实现一个子类，你可以在你的实现中显式调用超类的方法，即使你覆盖了这个方法，例如：

  [self overriddenMethod]; //调用子类的方法
 [super overriddenMethod]; //调用超类的方法
  

如果你想从子类实现之外的地方调用超类的方法，即：

  [[object super] overriddenMethod]; // crashes 
  

这是否可能？通过扩展，可以在实现中上升多个级别，即：

  [[super super] overriddenMethod ]; //这将工作吗？ 
  

解决方案

一个类别方法，它为你：

   - （void）callSuperMethod {[super overriddenMethod]; } 
  

事实上，没有更方便的方法可以做到这一点。 >

If you're implementing a subclass, you can, within your implementation, explicitly call the superclass's method, even if you've overridden that method, i.e.:

[self overriddenMethod]; //calls the subclass's method
[super overriddenMethod]; //calls the superclass's method

What if you want to call the superclass's method from somewhere outside the subclass's implementation, i.e.:

[[object super] overriddenMethod]; //crashes

Is this even possible? And by extension, is it possible to go up more than one level within the implementation, i.e.:

[[super super] overriddenMethod]; //will this work?

解决方案

A more pleasant option (for debugging) is to add a category method which does it for you:

- (void) callSuperMethod { [super overriddenMethod]; }

The fact that there’s no more convenient way to do this is very much by design.

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