如何将接口用作 C# 泛型类型约束? [英] How can I use interface as a C# generic type constraint?

问题描述

有没有办法得到下面的函数声明?

Is there a way to get the following function declaration?

public bool Foo<T>() where T : interface;

即.其中 T 是接口类型(类似于 where T : class 和 struct).

ie. where T is an interface type (similar to where T : class, and struct).

目前我已经解决了:

public bool Foo<T>() where T : IBase;

其中 IBase 被定义为一个空接口，它被我所有的自定义接口继承......不理想，但它应该可以工作......你为什么不能定义泛型类型必须是接口?

Where IBase is defined as an empty interface that is inherited by all my custom interfaces... Not ideal, but it should work... Why can't you define that a generic type must be an interface?

对于它的价值，我想要这个，因为 Foo 在需要接口类型的地方进行反射......我可以将它作为普通参数传入并在函数本身中进行必要的检查，但这似乎更类型安全(而且我认为性能更高一些，因为所有检查都是在编译时完成的).

For what it's worth, I want this because Foo is doing reflection where it needs an interface type... I could pass it in as a normal parameter and do the necessary checking in the function itself, but this seemed a lot more typesafe (and I suppose a little more performant, since all the checks are done at compiletime).

推荐答案

最接近你能做的(除了你的基本接口方法)是where T : class"，意思是引用类型.没有表示任何接口"的语法.

The closest you can do (except for your base-interface approach) is "where T : class", meaning reference-type. There is no syntax to mean "any interface".

此(where T : class")用于，例如，在 WCF 中将客户端限制为服务合同(接口).

This ("where T : class") is used, for example, in WCF to limit clients to service contracts (interfaces).

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