C＃泛型不会允许代理类型约束 [英] C# Generics won't allow Delegate Type Constraints

问题描述

时可以定义在C＃中的一类，这样

Is it possible to define a class in C# such that

class GenericCollection<T> : SomeBaseCollection<T> where T : Delegate

我不能为我的生活在.NET 3.5做到这一点，昨晚。我试图用

I couldn't for the life of me accomplish this last night in .NET 3.5. I tried using

委托，代表，动作＆LT; T＆GT;和Func键＆LT; T，T＆GT;

在我看来，这应该是在某种程度上允许的。我想实现我自己的EventQueue。

It seems to me that this should be allowable in some way. I'm trying to implement my own EventQueue.

最后我只是在做这个[原始近似提醒您。

I ended up just doing this [primitive approximation mind you].

internal delegate void DWork();

class EventQueue {
    private Queue<DWork> eventq;
}

但后来我失去了重用为不同类型的功能相同的定义的能力。

But then I lose the ability to reuse the same definition for different types of functions.

思考？

推荐答案

若干类是不可用作为一般约束上 - 枚举是另一个

A number of classes are unavailable as generic contraints - Enum being another.

有关代表，你可以得到的最接近的是：班，可能使用反射来检查（例如，在静态构造函数）的T的是的委托：

For delegates, the closest you can get is ": class", perhaps using reflection to check (for example, in the static constructor) that the T is a delegate:

    static GenericCollection()
    {
        if (!typeof(T).IsSubclassOf(typeof(Delegate)))
        {
            throw new InvalidOperationException(typeof(T).Name + " is not a delegate type");
        }
    }

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