如何在C＃中有一组枚举值？ [英] How to have a set of enumeration values in C#?

问题描述

假设我有枚举：

namespace System.Windows.Forms
{
   public enum DialogResult { None, OK, Cancel, Abort, Retry, Ignore, Yes, No }
}

我想声明一个>set由这些枚举类型组成

i want to declare a "set" made up of these enumerated types

ShowForm(Form frm, DialogResults allowedResults)

在其他语言中，您将声明：

In other languages you would declare:

public DialogResults = set of DialogResult;

然后我可以使用

ShowForm(frm, DialogResult.OK | DialogResult.Retry);

C＃具有 标志 的概念，伪代码：

C# has the notion of Flags, pseudocode:

[Flags]
public enum DialogResults { DialogResult.None, DialogResult.OK, DialogResult.Cancel, DialogResult.Abort, DialogResult.Retry, DialogResult.Ignore, DialogResult.Yes, DialogResult.No }

这不是真正的代码 - 标志不会指示编译器创建一组标志。

problem with that it's not real code - Flags does not instruct the compiler to create a set of flags.

• 在某种情况下，该类型应该只允许另一个一个值（ DialogResult ）


• 情况下，该类型应允许多个值（ DialogResults ）

• in one case the type should only allow one value (DialogResult)
• in another case the type should allow multiple values of above (DialogResults)

我有一个枚举类型的set？

注意：我假设在C＃中是不可能的。如果是这样的答案：可以这么说 - 问题得到回答。

Note: i assume it's not possible in C#. If that's the answer: it's okay to say so - the question is answered.

注意：只是因为我相信C＃语言没有这个功能并不意味着没有这个功能 - 我可以只是没有找到它。

Note: Just because i believe C# language doesn't have the feature doesn't mean it doesn't have the feature - i may just not have found it yet.

---

更新：另一个例子：

假设我有一个枚举：

public enum PatronTier 
{ 
    Gold = 1,      
    Platinum = 2,  
    Diamond = 3,   
    SevenStar = 7  //Yes, seven
}

我想声明由这些枚举类型组成的set >

i want to declare a "set" made up of these enumerated types

public Tournament
{
   public PatronTiers EligibleTiers { get; set; }
}

在其他语言中，您将声明：

In other languages you would declare:

public PatronTiers = set of PatronTier;

然后我可以使用：

tournament.EligibleTiers = PatronTier.Gold | PatronTier.SevenStar;

C＃具有 标志 的概念，伪代码：

C# has the notion of Flags, pseudocode:

[Flags]
public enum PatronTiers { PatronTier.Gold, PatronTier.Platinum, PatronTier.Diamond, PatronTier.SevenStar }

该问题不是真正的代码。

problem with that it's not real code.

我如何拥有枚举类型的set？

How can i have a "set" of enumerated types?

推荐答案

像你想要一系列的东西。在C＃中有数组类型，但直接 相当于编译器支持的例子，最接近的就是 DialogResults [] 数组 DialogResults 。

Seems like you want an array of things. There are array types in C#, but nothing that is directly equivalent to your examples in terms of compiler support, closest is perhaps DialogResults[], an array of DialogResults.

尝试提供一个 HashSet 你允许的项目 HashSet< T> 实现 ISet< T> ，通常最好是针对接口而不是具体类型，特别是方法签名：

Try supplying a HashSet of the items you allow. HashSet<T> implements ISet<T>, and it's usually best to work against interfaces than concrete types, especially for method signatures:

ShowForm(Form frm, ISet<DialogResults> allowedResults);

然后，您可以使用包含来测试项目：

Then you can use Contains to test for items:

if (allowedResults.Contains(DialogResults.OK))
{
}

有些无意义的选择：，您可以随时实现自己的 Set< ;枚举> 使用 Jon Skeet的无约束旋律进行输入你可以从调用者的角度来看一个更好的语法，并且更接近你的例子。

Somewhat pointless alternative: you could always implement your own Set<Enum> type using Jon Skeet's Unconstrained Melody to give you a nicer syntax from the perspective of the caller and get a little closer to your examples.

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