为什么会出现不带参数没有IsNullOrEmpty重载方法？ [英] Why is there no IsNullOrEmpty overload method without parameters?

问题描述

在试图找出一个字符串为null或空，我平时都串了。这就是为什么我本来期望效用函数，如String.IsNullOrEmpty（）不带参数的工作：

When trying to figure out if a string is null or empty, I usually have the string already. That's why I would have expected a utility function such as String.IsNullOrEmpty() to work without parameters:

String myString;
bool test=myString.IsNullOrEmpty();

不过，这是不行的，因为IsNullOrEmpty需要一个字符串参数。相反，我必须写：

However, this does not work, because IsNullOrEmpty expects a String parameter. Instead, I have to write:

String myString;
bool test=String.IsNullOrEmpty(myString);

为什么会这样？这似乎不必要的沉闷。当然，我可以很容易地为这个自己的扩展方法，但它似乎是一个非常明显的遗漏，所以我想知道是否有任何好的原因。我不能相信，这个函数的参数的重载刚刚被微软遗忘。

Why is this so? It seems unnecessarily clunky. Of course I can easily write own extension method for this, but it seems like a very obvious omission, so I am wondering if there is any good reason for this. I can't believe that the parameterless overload of this function has just been forgotten by Microsoft.

推荐答案

这个方法已经存在了很长的扩展方法添加到C＃之前，而之前扩展方法，没有办法确定一个实例方法/属性，如 xyz.IsNullOrEmpty（），你仍然可以调用，如果 XYZ 是无效。

This method has been around long before extension methods were added to C#, and before extension methods, there was no way to define an instance method/property such as xyz.IsNullOrEmpty() that you could still call if xyz was null.

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