如何将委托转换为相同的委托? [英] How to convert delegate to identical delegate?

问题描述

对委托有两个描述:首先，在第三方程序集中:

There are two descriptions of the delegate: first, in a third-party assembly:

public delegate void ClickMenuItem (object sender, EventArgs e)

秒，标准:

public delegate void EventHandler (object sender, EventArgs e);

我正在尝试编写一种方法，该方法将接收EventHandler类型的参数，并将使用参数ClickMenuItem调用第三方库.

I'm trying to write a method that will receive a parameter of type EventHandler and will call third-party library, with the parameter ClickMenuItem.

如何将ClickMenuItem转换为EventHandler?

How to convert the ClickMenuItem to EventHandler?

推荐答案

幸运的是，它很简单.您可以只写:

Fortunately, it's simple. You can just write:

ClickMenuItem clickMenuItem = ...; // Wherever you get this from
EventHandler handler = new EventHandler(clickMenuItem);

相反:

EventHandler handler = ...;
ClickMenuItem clickMenuItem = new ClickMenuItem(handler);

这甚至可以在C#1.0中使用.请注意，如果您随后更改了原始变量的值，则不会的更改将反映在已转换"变量中.例如:

This will even work in C# 1.0. Note that if you then change the value of the original variable, that change won't be reflected in the "converted" one. For example:

ClickMenuItem click = new ClickMenuItem(SomeMethod);
EventHandler handler = new EventHandler(click);
click = null;

handler(this, EventArgs.Empty); // This will still call SomeMethod

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