字符串和枚举相互转换

定义一个枚举：
  private enum myType
    {
        a = 1,
        b = 2,
        c = 3,
        lao = 4
    }

//字符串转枚举
 bool TryParse = Enum.IsDefined(typeof(myType), "a");
        if (TryParse)
        {
            object m = Enum.Parse(typeof(myType), "c");
            myType t = (myType)m;
        }

//枚举转字符串
myType.a.ToString();