我的枚举由以下值组成:
private enum PublishStatusses{
NotCompleted,
Completed,
Error
};
我希望能够以用户友好的方式输出这些值。 我不需要再从字符串到值。
我的枚举由以下值组成:
private enum PublishStatusses{
NotCompleted,
Completed,
Error
};
我希望能够以用户友好的方式输出这些值。 我不需要再从字符串到值。
当前回答
我使用一个泛型类来存储枚举/描述对,并使用一个嵌套的helper类来获取描述。
枚举:
enum Status { Success, Fail, Pending }
泛型类:
注意:由于泛型类不能被枚举约束,我用struct来代替约束,并在构造函数中检查enum。
public class EnumX<T> where T : struct
{
public T Code { get; set; }
public string Description { get; set; }
public EnumX(T code, string desc)
{
if (!typeof(T).IsEnum) throw new NotImplementedException();
Code = code;
Description = desc;
}
public class Helper
{
private List<EnumX<T>> codes;
public Helper(List<EnumX<T>> codes)
{
this.codes = codes;
}
public string GetDescription(T code)
{
EnumX<T> e = codes.Where(c => c.Code.Equals(code)).FirstOrDefault();
return e is null ? "Undefined" : e.Description;
}
}
}
用法:
EnumX<Status>.Helper StatusCodes = new EnumX<Status>.Helper(new List<EnumX<Status>>()
{
new EnumX<Status>(Status.Success,"Operation was successful"),
new EnumX<Status>(Status.Fail,"Operation failed"),
new EnumX<Status>(Status.Pending,"Operation not complete. Please wait...")
});
Console.WriteLine(StatusCodes.GetDescription(Status.Pending));
其他回答
这是对Ray Booysen的代码的更新,使用通用的GetCustomAttributes方法和LINQ使事情变得更整洁。
/// <summary>
/// Gets the value of the <see cref="T:System.ComponentModel.DescriptionAttribute"/> on an struct, including enums.
/// </summary>
/// <typeparam name="T">The type of the struct.</typeparam>
/// <param name="enumerationValue">A value of type <see cref="T:System.Enum"/></param>
/// <returns>If the struct has a Description attribute, this method returns the description. Otherwise it just calls ToString() on the struct.</returns>
/// <remarks>Based on http://stackoverflow.com/questions/479410/enum-tostring/479417#479417, but useful for any struct.</remarks>
public static string GetDescription<T>(this T enumerationValue) where T : struct
{
return enumerationValue.GetType().GetMember(enumerationValue.ToString())
.SelectMany(mi => mi.GetCustomAttributes<DescriptionAttribute>(false),
(mi, ca) => ca.Description)
.FirstOrDefault() ?? enumerationValue.ToString();
}
我用扩展方法做到这一点:
public enum ErrorLevel
{
None,
Low,
High,
SoylentGreen
}
public static class ErrorLevelExtensions
{
public static string ToFriendlyString(this ErrorLevel me)
{
switch(me)
{
case ErrorLevel.None:
return "Everything is OK";
case ErrorLevel.Low:
return "SNAFU, if you know what I mean.";
case ErrorLevel.High:
return "Reaching TARFU levels";
case ErrorLevel.SoylentGreen:
return "ITS PEOPLE!!!!";
default:
return "Get your damn dirty hands off me you FILTHY APE!";
}
}
}
根据本文档:https://learn.microsoft.com/pt-br/dotnet/api/system.enum.tostring?view=netframework-4.8
可以使用如下格式将枚举数转换为字符串:
public enum Example
{
Example1,
Example2
}
Console.WriteLine(Example.Example1.ToString("g"));
//Outputs: "Example1"
你可以在这个链接中看到所有可能的格式:https://learn.microsoft.com/pt-br/dotnet/api/system.string?view=netframework-4.8
我创建了一个反向扩展方法来将描述转换回enum值:
public static T ToEnumValue<T>(this string enumerationDescription) where T : struct
{
var type = typeof(T);
if (!type.IsEnum)
throw new ArgumentException("ToEnumValue<T>(): Must be of enum type", "T");
foreach (object val in System.Enum.GetValues(type))
if (val.GetDescription<T>() == enumerationDescription)
return (T)val;
throw new ArgumentException("ToEnumValue<T>(): Invalid description for enum " + type.Name, "enumerationDescription");
}
public enum MyEnum
{
[Description("Option One")]
Option_One
}
public static string ToDescriptionString(this Enum This)
{
Type type = This.GetType();
string name = Enum.GetName(type, This);
MemberInfo member = type.GetMembers()
.Where(w => w.Name == name)
.FirstOrDefault();
DescriptionAttribute attribute = member != null
? member.GetCustomAttributes(true)
.Where(w => w.GetType() == typeof(DescriptionAttribute))
.FirstOrDefault() as DescriptionAttribute
: null;
return attribute != null ? attribute.Description : name;
}