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，使得

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 中完成这件事.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、动作和 Func

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

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

我最终只是这样做了 [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

许多类不能作为通用约束 - Enum 是另一个.

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

对于委托，你能得到的最接近的是:class"，也许使用反射来检查(例如，在静态构造函数中)T 是一个委托:

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");
    }
}

这篇关于C#泛型不允许委托类型约束的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！