在C＃匿名委托 [英] anonymous delegates in C#

问题描述

我不能是唯一一个累了定义和命名委托只是一些单个呼叫，需要一个委托。例如，我想叫.REFRESH（）从可能的其他线程的形式，所以我写了这个代码：

I can't be the only one getting tired of defining and naming a delegate for just a single call to something that requires a delegate. For example, I wanted to call .Refresh() in a form from possibly other threads, so I wrote this code:

private void RefreshForm()
{
    if (InvokeRequired)
        Invoke(new InvokeDelegate(Refresh));
    else
        Refresh();
}

我甚至不确定我对，我刚读不够的害怕，它不会在一些后期工作。结果
InvokeDelegate在另一个文件实际上宣告，但我的真正的需要专门只为这一个完整的代表？不存在任何泛型委托呢？结果
我的意思是，例如，有一个笔类，但也有笔。笔的选的让你不要重拍整个事情。这是不一样的，但我希望你明白我的意思。

I'm not even sure I have to, I just read enough to be scared that it won't work at some later stage.
InvokeDelegate is actually declared in another file, but do I really need an entire delegate dedicated just for this? aren't there any generic delegates at all?
I mean, for example, there's a Pen class, but there's also Pens.pen-of-choice so you don't have to remake the whole thing. It's not the same, but I hope you understand what I mean.

推荐答案

是的。在.NET 3.5，您可以使用 Func键并的Action 代表。该Func键代表返回一个值，而行动委托返回void。下面是类型名称将是什么样子：

Yes. In .NET 3.5 you can use Func and Action delegates. The Func delegates return a value, while Action delegates return void. Here is what the type names would look like:

System.Func<TReturn> // (no arg, with return value)
System.Func<T, TReturn> // (1 arg, with return value)
System.Func<T1, T2, TReturn> // (2 arg, with return value)
System.Func<T1, T2, T3, TReturn> // (3 arg, with return value)
System.Func<T1, T2, T3, T4, TReturn> // (4 arg, with return value)

System.Action // (no arg, no return value)
System.Action<T> // (1 arg, no return value)
System.Action<T1, T2> // (2 arg, no return value)
System.Action<T1, T2, T3> // (3 arg, no return value)
System.Action<T1, T2, T3, T4> // (4 arg, no return value)

我不知道他们为什么停在4 ARGS每次，但它一直对我来说足够。

I don't know why they stopped at 4 args each, but it has always been enough for me.

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