C# 泛型不允许委托类型约束 [英] C# Generics won't allow Delegate Type Constraints

问题描述

是否可以在 C# 中定义一个类

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

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

昨晚我无法在 .NET 3.5 中完成此任务.我尝试使用

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

委托，委托，行动<T>和 Func<T,T>

在我看来，这在某种程度上应该是允许的.我正在尝试实现自己的 EventQueue.

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

我最终只是做了这个[请注意原始近似].

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

internal delegate void DWork();

class EventQueue {
    private Queue<DWork> eventq;
}

但是我失去了为不同类型的函数重用相同定义的能力.

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

想法?

推荐答案

许多类作为通用约束不可用 - Enum 是另一个.

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

对于委托，您可以获得的最接近的是:class"，可能使用反射来检查(例如，在静态构造函数中)T 是委托:

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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