C＃-一个Action<>是否可能具有多个方法签名？ [英] C# - Is it possible to have multiple method signatures for an Action<>?

问题描述

在C＃中，是否可以有一个对象，该对象具有用于操作或委托的多个方法签名？像这样：

In C#, is it possible to have an object that has multiple method signatures for an Action<> or delegate? Like this:

class Foo
{
    public Action<string> DoSomething;
    public Action<string, string> DoSomething;
}

class Bar
{
    public Bar()
    {
        Foo f1 = new Foo();
        f1.DoSomething = (s) => { Console.Write(s) };
        Foo f2 = new Foo();
        f2.DoSomething = (s1, s2) => { Console.Write(s1 + s2) };

        f1.DoSomething("Hi");
        f2.DoSomething("Hi","World");
    }
}

答案似乎是否定的，那是什么实施类似的正确方法？ （这正试图解决的实际问题已通过另一种方式解决，这只是出于好奇）

The answer seems to be no, so what is the proper way to implement something like that? (The actual problem this was trying to solve has been solved a different way, this is just curiosity at this point)

推荐答案

A delegate 是单个方法的抽象（当然，多个具有相似签名的方法可以由一个委托代表，但从调用者的角度来看，它的行为就像单个方法一样，因此在这里是无关紧要的。）单个方法具有多个签名没有任何意义。因此，委托实例具有特定的签名。重载解析对委托没有任何意义。这不是您要选择的方法组。您直接指向一种方法并说调用此方法。

A delegate is an abstraction of a single method (of course, several methods with similar signatures can be represented by a single delegate but from the caller's perspective, it behaves just like a single method, so that's irrelevant here.) It doesn't make sense for a single method to have multiple signatures. Hence, a delegate instance has a specific signature. Overload resolution does not have any meaning for delegates. It's not a method group you're choosing from. You're directly pointing to a method and saying "call this."

此问题的解决方案是什么？

What's the solution to this problem?

我不清楚实际的问题是什么。

It's not clear to me what the actual problem is. This might be what you're looking for:

class Foo {
    public Action<string> DoSomethingDelegate1;
    public Action<string,string> DoSomethingDelegate2;
    public void DoSomething(string s) { DoSomethingDelegate1(s); }
    public void DoSomething(string s, string t) { DoSomethingDelegate2(s, t); }
}

class Bar
{
    public Bar()
    {
        Foo f1 = new Foo();
        f1.DoSomethingDelegate1 = (s) => { Console.Write(s) };
        Foo f2 = new Foo();
        f2.DoSomethingDelegate2 = (s1, s2) => { Console.Write(s1 + s2) };

        f1.DoSomething("Hi");
        f2.DoSomething("Hi","World");
    }
}

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