如何限制一个泛型类型参数System.Enum [英] How to limit a generic type parameter to System.Enum

问题描述

可能显示的文件：
  <一href="http://stackoverflow.com/questions/7244/anyone-know-a-good-workaround-for-the-lack-of-an-enum-generic-constraint">Anyone知道一个很好的解决方法缺乏一个枚举通用的限制呢？
  <一href="http://stackoverflow.com/questions/79126/create-generic-method-constraining-t-to-an-enum">Create泛型方法约束T可枚举

Possible Duplicates:
Anyone know a good workaround for the lack of an enum generic constraint?
Create Generic method constraining T to an Enum

时可以限制泛型类型参数[我不知道这是正确的名称]到枚举？

Is is possible to limit the generic type parameter [I don't know if that's the right name] to an Enum?

例如我怎么做这样的事？

For example how do I do something like this?

//VB.NET
Function GetValues(Of T As System.Enum)(ByVal value As T) As IEnumerable(Of T)
    Return [Enum].GetValues(value.GetType)
End Function

//C#
public IEnumerable<T> GetValues<T>(T value) where T : System.Enum
{
    return Enum.GetValues(value.GetType());
}

---

更新

我终于用乔恩斯基特的约束旋律用于这一目的。感谢大家的贡献。

I eventually used Jon Skeet's Unconstrained Melody for that purpose. Thanks to you all for your contributions.

推荐答案

不幸的是，你不能 - <一个href="http://connect.microsoft.com/VisualStudio/feedback/details/386194/allow-enum-as-generic-constraint-in-c">Microsoft关闭这个作为一个不会解决项。

Unfortunately, you cannot - Microsoft closed this one out as a won't fix item.

您可以把枚举的结构和使用，作为约束，而不是（我认为这是乔恩斯基特是如何做它的无约束的旋律？），但就是那种难看。

You can treat enums as structs and use that as the constraint instead (I think that was how Jon Skeet did it in Unconstrained Melody?) but that is kind of unsightly.

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