我有以下列举:
public enum AuthenticationMethod
{
FORMS = 1,
WINDOWSAUTHENTICATION = 2,
SINGLESIGNON = 3
}
然而问题是，当我请求AuthenticationMethod时，我需要“FORMS”这个词。表单而不是id
对于这个问题，我找到了以下解决方案(链接):
首先，我需要创建一个自定义属性“StringValue”:
public class StringValue : System.Attribute
{
private readonly string _value;
public StringValue(string value)
{
_value = value;
}
public string Value
{
get { return _value; }
}
}
然后我可以将这个属性添加到我的枚举器中:
public enum AuthenticationMethod
{
[StringValue("FORMS")]
FORMS = 1,
[StringValue("WINDOWS")]
WINDOWSAUTHENTICATION = 2,
[StringValue("SSO")]
SINGLESIGNON = 3
}
当然，我需要一些东西来检索StringValue:
public static class StringEnum
{
public static string GetStringValue(Enum value)
{
string output = null;
Type type = value.GetType();
//Check first in our cached results...
//Look for our 'StringValueAttribute'
//in the field's custom attributes
FieldInfo fi = type.GetField(value.ToString());
StringValue[] attrs =
fi.GetCustomAttributes(typeof(StringValue),
false) as StringValue[];
if (attrs.Length > 0)
{
output = attrs[0].Value;
}
return output;
}
}
很好，现在我已经有了工具来获取枚举器的字符串值。
然后我可以这样使用它:
string valueOfAuthenticationMethod = StringEnum.GetStringValue(AuthenticationMethod.FORMS);
好的，现在所有这些工作就像一个魅力，但我发现它有很多工作。我想知道有没有更好的解决办法。
我还尝试了一些字典和静态属性，但这也不是更好。
我的答案是，正在处理@user29964的答案(这是迄今为止最简单和最接近Enum的答案)
public class StringValue : System.Attribute
{
private string _value;
public StringValue(string value)
{
_value = value;
}
public string Value
{
get { return _value; }
}
public static string GetStringValue(Enum Flagvalue)
{
Type type = Flagvalue.GetType();
string[] flags = Flagvalue.ToString().Split(',').Select(x => x.Trim()).ToArray();
List<string> values = new List<string>();
for (int i = 0; i < flags.Length; i++)
{
FieldInfo fi = type.GetField(flags[i].ToString());
StringValue[] attrs =
fi.GetCustomAttributes(typeof(StringValue),
false) as StringValue[];
if (attrs.Length > 0)
{
values.Add(attrs[0].Value);
}
}
return String.Join(",", values);
}
使用
[Flags]
public enum CompeteMetric
{
/// <summary>
/// u
/// </summary>
[StringValue("u")]//Json mapping
Basic_UniqueVisitors = 1 //Basic
,
/// <summary>
/// vi
/// </summary>
[StringValue("vi")]//json mapping
Basic_Visits = 2// Basic
,
/// <summary>
/// rank
/// </summary>
[StringValue("rank")]//json mapping
Basic_Rank = 4//Basic
}
例子
CompeteMetric metrics = CompeteMetric.Basic_Visits | CompeteMetric.Basic_Rank;
string strmetrics = StringValue.GetStringValue(metrics);
它会返回
“vi,排名”
我使用系统中的Description属性。ComponentModel名称空间。简单地装饰枚举，然后使用下面的代码来检索它:
public static string GetDescription<T>(this object enumerationValue)
where T : struct
{
Type type = enumerationValue.GetType();
if (!type.IsEnum)
{
throw new ArgumentException("EnumerationValue must be of Enum type", "enumerationValue");
}
//Tries to find a DescriptionAttribute for a potential friendly name
//for the enum
MemberInfo[] memberInfo = type.GetMember(enumerationValue.ToString());
if (memberInfo != null && memberInfo.Length > 0)
{
object[] attrs = memberInfo[0].GetCustomAttributes(typeof(DescriptionAttribute), false);
if (attrs != null && attrs.Length > 0)
{
//Pull out the description value
return ((DescriptionAttribute)attrs[0]).Description;
}
}
//If we have no description attribute, just return the ToString of the enum
return enumerationValue.ToString();
}
举个例子:
public enum Cycle : int
{
[Description("Daily Cycle")]
Daily = 1,
Weekly,
Monthly
}
这段代码很好地满足了不需要“友好名称”的枚举，只返回枚举的. tostring()。
我的答案是，正在处理@user29964的答案(这是迄今为止最简单和最接近Enum的答案)
public class StringValue : System.Attribute
{
private string _value;
public StringValue(string value)
{
_value = value;
}
public string Value
{
get { return _value; }
}
public static string GetStringValue(Enum Flagvalue)
{
Type type = Flagvalue.GetType();
string[] flags = Flagvalue.ToString().Split(',').Select(x => x.Trim()).ToArray();
List<string> values = new List<string>();
for (int i = 0; i < flags.Length; i++)
{
FieldInfo fi = type.GetField(flags[i].ToString());
StringValue[] attrs =
fi.GetCustomAttributes(typeof(StringValue),
false) as StringValue[];
if (attrs.Length > 0)
{
values.Add(attrs[0].Value);
}
}
return String.Join(",", values);
}
使用
[Flags]
public enum CompeteMetric
{
/// <summary>
/// u
/// </summary>
[StringValue("u")]//Json mapping
Basic_UniqueVisitors = 1 //Basic
,
/// <summary>
/// vi
/// </summary>
[StringValue("vi")]//json mapping
Basic_Visits = 2// Basic
,
/// <summary>
/// rank
/// </summary>
[StringValue("rank")]//json mapping
Basic_Rank = 4//Basic
}
例子
CompeteMetric metrics = CompeteMetric.Basic_Visits | CompeteMetric.Basic_Rank;
string strmetrics = StringValue.GetStringValue(metrics);
它会返回
“vi,排名”
我使用了上述几个建议的组合，并结合了一些缓存。现在，我从网上找到的一些代码中得到了这个想法，但我既不记得是从哪里得到的，也不记得是怎么找到的。所以如果有人发现了一些相似的东西，请在归因处发表评论。
无论如何，使用涉及到类型转换器，所以如果你绑定到UI，它'只是工作'。您可以使用Jakub的模式进行扩展，通过从类型转换器初始化到静态方法来实现快速代码查找。
基本使用量是这样的
[TypeConverter(typeof(CustomEnumTypeConverter<MyEnum>))]
public enum MyEnum
{
// The custom type converter will use the description attribute
[Description("A custom description")]
ValueWithCustomDescription,
// This will be exposed exactly.
Exact
}
自定义枚举类型转换器的代码如下:
public class CustomEnumTypeConverter<T> : EnumConverter
where T : struct
{
private static readonly Dictionary<T,string> s_toString =
new Dictionary<T, string>();
private static readonly Dictionary<string, T> s_toValue =
new Dictionary<string, T>();
private static bool s_isInitialized;
static CustomEnumTypeConverter()
{
System.Diagnostics.Debug.Assert(typeof(T).IsEnum,
"The custom enum class must be used with an enum type.");
}
public CustomEnumTypeConverter() : base(typeof(T))
{
if (!s_isInitialized)
{
Initialize();
s_isInitialized = true;
}
}
protected void Initialize()
{
foreach (T item in Enum.GetValues(typeof(T)))
{
string description = GetDescription(item);
s_toString[item] = description;
s_toValue[description] = item;
}
}
private static string GetDescription(T optionValue)
{
var optionDescription = optionValue.ToString();
var optionInfo = typeof(T).GetField(optionDescription);
if (Attribute.IsDefined(optionInfo, typeof(DescriptionAttribute)))
{
var attribute =
(DescriptionAttribute)Attribute.
GetCustomAttribute(optionInfo, typeof(DescriptionAttribute));
return attribute.Description;
}
return optionDescription;
}
public override object ConvertTo(ITypeDescriptorContext context,
System.Globalization.CultureInfo culture,
object value, Type destinationType)
{
var optionValue = (T)value;
if (destinationType == typeof(string) &&
s_toString.ContainsKey(optionValue))
{
return s_toString[optionValue];
}
return base.ConvertTo(context, culture, value, destinationType);
}
public override object ConvertFrom(ITypeDescriptorContext context,
System.Globalization.CultureInfo culture, object value)
{
var stringValue = value as string;
if (!string.IsNullOrEmpty(stringValue) && s_toValue.ContainsKey(stringValue))
{
return s_toValue[stringValue];
}
return base.ConvertFrom(context, culture, value);
}
}
}
选项1:
public sealed class FormsAuth
{
public override string ToString{return "Forms Authtentication";}
}
public sealed class WindowsAuth
{
public override string ToString{return "Windows Authtentication";}
}
public sealed class SsoAuth
{
public override string ToString{return "SSO";}
}
然后
object auth = new SsoAuth(); //or whatever
//...
//...
// blablabla
DoSomethingWithTheAuth(auth.ToString());
选项2:
public enum AuthenticationMethod
{
FORMS = 1,
WINDOWSAUTHENTICATION = 2,
SINGLESIGNON = 3
}
public class MyClass
{
private Dictionary<AuthenticationMethod, String> map = new Dictionary<AuthenticationMethod, String>();
public MyClass()
{
map.Add(AuthenticationMethod.FORMS,"Forms Authentication");
map.Add(AuthenticationMethod.WINDOWSAUTHENTICATION ,"Windows Authentication");
map.Add(AuthenticationMethod.SINGLESIGNON ,"SSo Authentication");
}
}
我如何解决这个扩展方法:
using System.ComponentModel;
public static string GetDescription(this Enum value)
{
var descriptionAttribute = (DescriptionAttribute)value.GetType()
.GetField(value.ToString())
.GetCustomAttributes(false)
.Where(a => a is DescriptionAttribute)
.FirstOrDefault();
return descriptionAttribute != null ? descriptionAttribute.Description : value.ToString();
}
枚举:
public enum OrderType
{
None = 0,
[Description("New Card")]
NewCard = 1,
[Description("Reload")]
Refill = 2
}
用法(其中o.OrderType是一个与enum同名的属性):
o.OrderType.GetDescription()
这给了我一个字符串的“新卡”或“重载”，而不是实际的enum值NewCard和重新填充。
