什么是C＃中的方法组？ [英] What is a method group in C#?

问题描述

我也经常遇到的错误，如在案件，从方法组到串不能转换，如：

I have often encountered an error such as "cannot convert from 'method group' to 'string'" in cases like:

var list = new List<string>();
// ... snip
list.Add(someObject.ToString);

当然，

有一个错字的最后一行，因为我忘了在调用括号的ToString 。正确的形式是：

of course there was a typo in the last line because I forgot the invocation parentheses after ToString. The correct form would be:

var list = new List<string>();
// ... snip
list.Add(someObject.ToString()); // <- notice the parentheses

不过我来不知道什么是方法组。 <一href="http://www.google.com/search?hl=ro&client=opera&rls=en&hs=yqM&num=100&newwindow=1&q=what+is+a+method+group+.net&btnG=C%C4%83utare&lr=">Google是没有太大的帮助，也不 MSDN 。

However I came to wonder what is a method group. Google isn't much of a help nor MSDN.

推荐答案

方法组是对的的一套方法的名称的（这可能只是一个） - 即理论上的的ToString 方法可以有多个重载（加任何扩展方法）：的ToString（），的ToString（字符串格式）等 - 因此的ToString 本身是一种方法组

A method group is the name for a set of methods (that might be just one) - i.e. in theory the ToString method may have multiple overloads (plus any extension methods): ToString(), ToString(string format), etc - hence ToString by itself is a "method group".

这通常可以转换方法组到（类型）代表通过使用重载 - 而不是一个字符串等;它没有意义。

It can usually convert a method group to a (typed) delegate by using overload resolution - but not to a string etc; it doesn't make sense.

一旦添加了括号，再一次;重载踢，你已经清楚地确定了一个方法调用。

Once you add parentheses, again; overload resolution kicks in and you have unambiguously identified a method call.

这篇关于什么是C＃中的方法组？的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！