将[Flags]枚举序列化为字符串

Question

有没有办法指定类中的[Flags]枚举字段应该序列化为字符串表示形式（例如“Sunday，Tuesday”）而不是整数值（例如5）？

更具体地说，当在Web服务中返回以下SomeClass类型时，我想获得一个名为“Days”的字符串字段，但我得到一个数字字段。

[Flags]
public enum DaysOfWeek
{
    Sunday = 0x1,
    Monday = 0x2,
    Tuesday = 0x4,
    Wednesday = 0x8,
    Thursday = 0x10,
    Friday = 0x20,
    Saturday = 0x40
}
[DataContract]
public class SomeClass
{
    [DataMember]
    public DaysOfWeek Days;
}

Answer 1

不，但您可以通过创建一个执行相同操作的结构来定义自己的“枚举”，

public struct MyDayOfWeek
{
    private int iVal;
    private bool def;

    internal int Value
    {
        get { return iVal; }
        set { iVal = value; }
    }
    public bool Defined
    {
        get { return def; }
        set { def = value; }
    }
    public bool IsNull { get { return !Defined; } }

    private MyDayOfWeek(int i)
    {
       iVal = i;
       def = true;
    }           

    #region constants
    private const int Monday = new MyDayOfWeek(1);
    private const int Tuesday = new MyDayOfWeek(2);
    private const int Wednesday = new MyDayOfWeek(3);
    private const int Thursday = new MyDayOfWeek(4);
    private const int Friday = new MyDayOfWeek(5);
    private const int Saturday = new MyDayOfWeek(6);
    private const int Sunday = new MyDayOfWeek(7);
    #endregion constants

    public override string ToString()
    {
        switch (iVal)
        {
            case (1): return "Monday";
            case (2): return "Tuesday";
            case (3): return "Wednesday";
            case (4): return "Thursday";
            case (5): return "Friday";
            case (6): return "Saturday";
            case (7): return "Sunday";
        }
    }
}

Answer 2

我不知道DataContractSerializer，但是对于XmlSerializer，它会被序列化为“星期二星期二”。我不是WCF专家，但我想我在某处读到你可以指定必须使用XmlSerializer而不是DataContractSerializer

Answer 3

我能想到的最好的方法是在MyEnum上创建一个遍历MyEnum.GetMembers（）的扩展方法，以及在MyEnum被序列化的情况下按位和非零的方法，调用ToString（）并聚合到输出字符串。