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

public class DataType
{
    private readonly string value;
    private static readonly Dictionary<string, DataType> predefinedValues;

    public static readonly DataType Json = new DataType("json");
    public static readonly DataType Xml = new DataType("xml");
    public static readonly DataType Text = new DataType("text");
    public static readonly DataType Html = new DataType("html");
    public static readonly DataType Binary = new DataType("binary");

    static DataType()
    {
        predefinedValues = new Dictionary<string, DataType>();
        predefinedValues.Add(Json.Value, Json);
        predefinedValues.Add(Xml.Value, Xml);
        predefinedValues.Add(Text.Value, Text);
        predefinedValues.Add(Html.Value, Html);
        predefinedValues.Add(Binary.Value, Binary);
    }

    private DataType(string value)
    {
        this.value = value;
    }

    public static DataType Parse(string value)
    {
        var exception = new FormatException($"Invalid value for type {nameof(DataType)}");
        if (string.IsNullOrEmpty(value))
            throw exception;

        string key = value.ToLower();
        if (!predefinedValues.ContainsKey(key))
            throw exception;

        return predefinedValues[key];
    }

    public string Value
    {
        get { return value; }
    }
}

其他回答

摘自@EvenMien,并添加了一些评论。(也适用于我自己的用例)

public struct AgentAction
{
    private AgentAction(string value) { Value = value; }

    public string Value { get; private set; }

    public override string ToString() { return this.Value; }
    
    public static AgentAction Login = new AgentAction("Login");
    public static AgentAction Logout = new AgentAction("Logout");

    public static implicit operator string(AgentAction action) { return action.ToString(); }
}

另一种处理这个问题的方法是,有一个枚举和一个字符串数组,将枚举值映射到字符串列表:

public enum GroupTypes
{
    TheGroup  = 0,
    TheOtherGroup 
}

string[] GroupTypesStr = {
    "OEM",
    "CMB"
};

你可以这样使用它:

Log.Write(GroupTypesStr[(int)GroupTypes.TheOtherGroup]);

它将提示CMB

优点:

简单干净的代码。 高性能(特别是与那些方法相比 使用类)

缺点:

易于混乱的列表时,编辑它,但这将是一个好的 短名单。

我做过类似的事情;

public enum BusinessUnits
{
    NEW_EQUIPMENT = 0,
    USED_EQUIPMENT = 1,
    RENTAL_EQUIPMENT = 2,
    PARTS = 3,
    SERVICE = 4,
    OPERATOR_TRAINING = 5
}

public class BusinessUnitService
{
    public static string StringBusinessUnits(BusinessUnits BU)
    {
        switch (BU)
        {
            case BusinessUnits.NEW_EQUIPMENT: return "NEW EQUIPMENT";
            case BusinessUnits.USED_EQUIPMENT: return "USED EQUIPMENT";
            case BusinessUnits.RENTAL_EQUIPMENT: return "RENTAL EQUIPMENT";
            case BusinessUnits.PARTS: return "PARTS";
            case BusinessUnits.SERVICE: return "SERVICE";
            case BusinessUnits.OPERATOR_TRAINING: return "OPERATOR TRAINING";
            default: return String.Empty;
        }
    }
}

用这个称呼它;

BusinessUnitService.StringBusinessUnits(BusinessUnits.PARTS)

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。

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?
  }
}