如何阻止一个超类方法被调用到一个子类 [英] how to block a superclass method to be called to a subclass

问题描述

我扩展了一个类的子类的功能，我做一些脏的东西，使超类方法危险（应用程序将挂在一个循环）在子类的上下文。我知道这不是一个天才的想法，但我要去低洼的水果，现在它会给我一些时间。哦，这是一个肮脏的工作，但有人必须这样做。

底线，我需要从外部阻止该方法，或者在直接调用超类时抛出异常。 （但我仍然使用它从子类，除非小心）。

这是最好的方法是什么？

UPDATE ---

所以这是我去的。我不是自我回答，因为Boaz的回答提到了多种有效的方式来做到这一点，这只是适合我的方式。在子类中，我突破了这样的方法：

   - （int）dangerMethod 
 {
 [ NSException raise：@危险！格式：@不调用直接发送这个方法到这个子类]; 
 return nil; 
} 
  

我将此标记为已回答，但显然这并不意味着

解决方案

只要在子类中重新实现不安全的方法，异常或重新实现它是安全的，只要新的实现不调用不安全的超类方法。

对于C ++团队在这里：Objective C doesn不允许你将方法标记为私有。您可以使用其类别系统将界面拆分为单独的文件（从而隐藏私有文件），但类上的所有方法都是公共的。

I'm extending the functionality of a class with a subclass, and I'm doing some dirty stuff that make superclass methods dangerous (app will hang in a loop) in the context of the subclass. I know it's not a genius idea, but I'm going for the low-hanging fruit, right now it's gonna save me some time. Oh it's a dirty job, but someone's gotta do it.

Bottom line, I need to either block that method from outside, or throw an exception when it's called directly to the superclass. (But I still use it from the subclass, except with care).

What would be the best way to do this?

UPDATE ---

So this is what I went for. I'm not self-answering, as Boaz' answer mentions multiple valid ways to do this, this is just the way that suited me. In the subclass, I overrode the method like this:

- (int)dangerousMethod
{
  [NSException raise:@"Danger!" format:@"Do not call send this method directly to this subclass"];
  return nil;
}

I'm marking this as answered, but evidently that doesn't mean it's closed, further suggestions are welcome.

解决方案

Just re-implement the unsafe method in your subclass and have it do nothing or throw an exception or re-implement it as safe, just as long as the new implementation doesn't call the unsafe superclass method.

For the C++ crew in here: Objective C doesn't let you mark methods as private. You can use its category system to split up the interface into separate files (thus hiding 'private' ones), but all methods on a class are public.

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