我知道下面是不可能的,因为枚举的类型必须是int

enum GroupTypes
{
    TheGroup = "OEM",
    TheOtherGroup = "CMB"
}

从我的数据库中,我得到了一个不全面的代码字段(OEM和CMBs)。我想让这个字段成为一个枚举或其他可以理解的东西。因为如果目标是可读性,解决方案就应该简洁。

我还有其他选择吗?


当前回答

使用带有常量的静态类如何?

static class GroupTypes
{
  public const string TheGroup = "OEM";
  public const string TheOtherGroup = "CMB";
}

void DoSomething(string groupType)
{
  if(groupType == GroupTypes.TheGroup)
  {
    // Be nice
  }  
  else if (groupType == GroupTypes.TheOtherGroup)
  {
    // Continue to be nice
  }
  else
  {
    // unexpected, throw exception?
  }
}

其他回答

为什么不使用相同的枚举,而只是调用.ToString()?

using System;

public class EnumSample
{
    enum Holidays
    {
        Christmas = 1,
        Easter = 2
    };

    public static void Main()
    {
        Enum myHolidays = Holidays.Christmas;
        Console.WriteLine("The value of this instance is '{0}'", myHolidays.ToString());
    }
}

使用带有常量的静态类如何?

static class GroupTypes
{
  public const string TheGroup = "OEM";
  public const string TheOtherGroup = "CMB";
}

void DoSomething(string groupType)
{
  if(groupType == GroupTypes.TheGroup)
  {
    // Be nice
  }  
  else if (groupType == GroupTypes.TheOtherGroup)
  {
    // Continue to be nice
  }
  else
  {
    // unexpected, throw exception?
  }
}

如果我理解正确,你需要一个从字符串到enum的转换:

enum GroupTypes {
    Unknown = 0,
    OEM = 1,
    CMB = 2
}
static GroupTypes StrToEnum(string str){
    GroupTypes g = GroupTypes.Unknown;
    try {
        object o = Enum.Parse(typeof(GroupTypes), str, true);
        g = (GroupTypes)(o ?? 0);
    } catch {
    }
    return g;
}
// then use it like this
GroupTypes g1 = StrToEnum("OEM");
GroupTypes g2 = StrToEnum("bad value");

如果您愿意,可以使用枚举类型的泛型使其更加花哨。

如果你喜欢自己编写扩展,上面有几个很好的答案

我使用CodeHelper.Core.Extensions

enum GroupTypes
{

    [StringValue("OEM")] TheGroup,
    [StringValue("CMB")] TheOtherGroup = "CMB"
}

GroupTypes.TheOtherGroup.ToStringValue()

如果你没有将StringValue属性添加到值中,扩展将返回正常名称(.ToTring()) 并且超级容易添加空格和其他通常不允许的字符,如空格或以数字开头

基于https://stackoverflow.com/a/1343517/1818723,我提出了一个枚举与TryParse方法

public class FancyStringEnum
{
    private FancyStringEnum(string value) { Value = value; }

    public string Value { get; private set; }

    private static List<FancyStringEnum> choices = new List<FancyStringEnum>
    {
        new FancyStringEnum("Small") ,
        new FancyStringEnum("Big Thing") ,
        new FancyStringEnum("Value with Spaces")
    };

    public static FancyStringEnum Small { get { return choices[0]; } }
    public static FancyStringEnum BigThing { get { return choices[1]; } }
    public static FancyStringEnum ValueWithSpaces { get { return choices[2]; } }

    public override string ToString()
    {
        return Value;
    }

    public static bool TryParse(string value, bool ignoreCase, out FancyStringEnum result)
    {
        var sc = StringComparison.InvariantCulture;
        if (ignoreCase)
            sc = StringComparison.InvariantCultureIgnoreCase;

        foreach (var choice in choices)
        {

            if (choice.Value.Equals(value, sc))
            {
                result = choice;
                return true;
            }
        }

        result = new FancyStringEnum(null);
        return false;
    }

    public static FancyStringEnum Parse(string value, bool ignoreCase)
    {
        var sc = StringComparison.InvariantCulture;
        if (ignoreCase)
            sc = StringComparison.InvariantCultureIgnoreCase;

        foreach (var choice in choices)
        {

            if (choice.Value.Equals(value, sc))
            {
                return choice;
            }
        }

        return new FancyStringEnum(null);
    }
}

传入类型安全的字符串值作为参数:

public static void Do(string message, FancyStringEnum value)
{
    if (value == FancyStringEnum.Small)
    {
        //do something
    } else if (value == FancyStringEnum.BigThing)
    {
        //do something else
    }
}

TryParse和Parse在行动:

string something = "something"; //substiture with "small" to see it parsed 
if (FancyStringEnum.TryParse(something, true, out var se))
    Console.WriteLine(se.Value);
else
    Console.WriteLine($"unable to parse {something}");

//or    

var v2 = FancyStringEnum.Parse(something, true);
if (v2.Value == null)
    Console.WriteLine($"unable to parse {something}");
else
    Console.WriteLine(v2.Value); //do something with parsed enum

    

是否可以提取基类,用更少的代码创建StringEnums