可能的重复:
通过描述属性查找枚举值
我有一个通用的扩展方法，从Enum中获得Description属性:
enum Animal
{
[Description("")]
NotSet = 0,
[Description("Giant Panda")]
GiantPanda = 1,
[Description("Lesser Spotted Anteater")]
LesserSpottedAnteater = 2
}
public static string GetDescription(this Enum value)
{
FieldInfo field = value.GetType().GetField(value.ToString());
DescriptionAttribute attribute
= Attribute.GetCustomAttribute(field, typeof(DescriptionAttribute))
as DescriptionAttribute;
return attribute == null ? value.ToString() : attribute.Description;
}
所以我可以做…
string myAnimal = Animal.GiantPanda.GetDescription(); // = "Giant Panda"
现在，我试着在另一个方向上算出等效函数，就像……
Animal a = (Animal)Enum.GetValueFromDescription("Giant Panda", typeof(Animal));
应该是相当直截了当的，它只是你以前的方法相反;
public static int GetEnumFromDescription(string description, Type enumType)
{
foreach (var field in enumType.GetFields())
{
DescriptionAttribute attribute
= Attribute.GetCustomAttribute(field, typeof(DescriptionAttribute))as DescriptionAttribute;
if(attribute == null)
continue;
if(attribute.Description == description)
{
return (int) field.GetValue(null);
}
}
return 0;
}
用法:
Console.WriteLine((Animal)GetEnumFromDescription("Giant Panda",typeof(Animal)));
应该是相当直截了当的，它只是你以前的方法相反;
public static int GetEnumFromDescription(string description, Type enumType)
{
foreach (var field in enumType.GetFields())
{
DescriptionAttribute attribute
= Attribute.GetCustomAttribute(field, typeof(DescriptionAttribute))as DescriptionAttribute;
if(attribute == null)
continue;
if(attribute.Description == description)
{
return (int) field.GetValue(null);
}
}
return 0;
}
用法:
Console.WriteLine((Animal)GetEnumFromDescription("Giant Panda",typeof(Animal)));
你不能扩展Enum，因为它是一个静态类。您只能扩展类型的实例。考虑到这一点，你必须自己创建一个静态方法来完成这个任务;下面应该工作时结合你现有的方法GetDescription:
public static class EnumHelper
{
public static T GetEnumFromString<T>(string value)
{
if (Enum.IsDefined(typeof(T), value))
{
return (T)Enum.Parse(typeof(T), value, true);
}
else
{
string[] enumNames = Enum.GetNames(typeof(T));
foreach (string enumName in enumNames)
{
object e = Enum.Parse(typeof(T), enumName);
if (value == GetDescription((Enum)e))
{
return (T)e;
}
}
}
throw new ArgumentException("The value '" + value
+ "' does not match a valid enum name or description.");
}
}
它的用法是这样的:
Animal giantPanda = EnumHelper.GetEnumFromString<Animal>("Giant Panda");
这个解决方案工作得很好，除非您有一个Web服务。
您需要执行以下操作，因为Description属性不可序列化。
[DataContract]
public enum ControlSelectionType
{
[EnumMember(Value = "Not Applicable")]
NotApplicable = 1,
[EnumMember(Value = "Single Select Radio Buttons")]
SingleSelectRadioButtons = 2,
[EnumMember(Value = "Completely Different Display Text")]
SingleSelectDropDownList = 3,
}
public static string GetDescriptionFromEnumValue(Enum value)
{
EnumMemberAttribute attribute = value.GetType()
.GetField(value.ToString())
.GetCustomAttributes(typeof(EnumMemberAttribute), false)
.SingleOrDefault() as EnumMemberAttribute;
return attribute == null ? value.ToString() : attribute.Value;
}
