@interface MyClass : NSObject{}
  

  - (void)show;
  

  @end
  

  @implementation MyClass
  

  - (void)show {
  

  NSLog(@"MyClass");
  

  }
  

  @end
  

  

  @interface MySubClass : MyClass
  

  {}
  

  @end
  

  @implementation MySubClass
  

  - (void)show {
  

  NSLog(@"MySubClass");
  

  }
  

  @end
  

  

  一个临时函数：
  

  - (void)show:(void *)temp {
  

  MyClass *mc = (MyClass *)temp;
  

  [mc show];
  

  }
  

  

  在主函数中调用：
  

  

  MySubClass *msc = [[MySubClass alloc] init];
  

  void *temp = (void *)msc;
  

  [self show:temp];
  

  

  控制台的结果：//MySubClass