我在我的模型中有一个属性叫做Promotion,它的类型是一个标志enum叫做UserPromotion。枚举成员的显示属性设置如下:
[Flags]
public enum UserPromotion
{
None = 0x0,
[Display(Name = "Send Job Offers By Mail")]
SendJobOffersByMail = 0x1,
[Display(Name = "Send Job Offers By Sms")]
SendJobOffersBySms = 0x2,
[Display(Name = "Send Other Stuff By Sms")]
SendPromotionalBySms = 0x4,
[Display(Name = "Send Other Stuff By Mail")]
SendPromotionalByMail = 0x8
}
现在我想要能够在我的视图中创建一个ul来显示我的Promotion属性的选定值。这就是我到目前为止所做的但问题是,我如何在这里获得显示名称?
<ul>
@foreach (int aPromotion in @Enum.GetValues(typeof(UserPromotion)))
{
var currentPromotion = (int)Model.JobSeeker.Promotion;
if ((currentPromotion & aPromotion) == aPromotion)
{
<li>Here I don't know how to get the display attribute of "currentPromotion".</li>
}
}
</ul>
对于这个问题,我有两个解决方案。
第一个解决方案是从enum中获取显示名称。
public enum CourseLocationTypes
{
[Display(Name = "On Campus")]
OnCampus,
[Display(Name = "Online")]
Online,
[Display(Name = "Both")]
Both
}
public static string DisplayName(this Enum value)
{
Type enumType = value.GetType();
string enumValue = Enum.GetName(enumType, value);
MemberInfo member = enumType.GetMember(enumValue)[0];
object[] attrs = member.GetCustomAttributes(typeof(DisplayAttribute), false);
string outString = ((DisplayAttribute)attrs[0]).Name;
if (((DisplayAttribute)attrs[0]).ResourceType != null)
{
outString = ((DisplayAttribute)attrs[0]).GetName();
}
return outString;
}
<h3 class="product-title white">@Model.CourseLocationType.DisplayName()</h3>
第二个解决方案是从枚举名称中获取显示名称,但在开发人员语言中它被称为patch。
public static string SplitOnCapitals(this string text)
{
var r = new Regex(@"
(?<=[A-Z])(?=[A-Z][a-z]) |
(?<=[^A-Z])(?=[A-Z]) |
(?<=[A-Za-z])(?=[^A-Za-z])", RegexOptions.IgnorePatternWhitespace);
return r.Replace(text, " ");
}
<div class="widget-box pt-0">
@foreach (var item in Enum.GetNames(typeof(CourseLocationType)))
{
<label class="pr-2 pt-1">
@Html.RadioButtonFor(x => x.CourseLocationType, item, new { type = "radio", @class = "iCheckBox control-label" }) @item.SplitOnCapitals()
</label>
}
@Html.ValidationMessageFor(x => x.CourseLocationType)
</div>
更新
第一个解决方案侧重于从enum中获取显示名称。下面的代码应该是您的问题的确切解决方案。
你可以为枚举使用这个helper类:
using System;
using System.Collections.Generic;
using System.ComponentModel.DataAnnotations;
using System.Linq;
using System.Reflection;
public static class EnumHelper<T>
where T : struct, Enum // This constraint requires C# 7.3 or later.
{
public static IList<T> GetValues(Enum value)
{
var enumValues = new List<T>();
foreach (FieldInfo fi in value.GetType().GetFields(BindingFlags.Static | BindingFlags.Public))
{
enumValues.Add((T)Enum.Parse(value.GetType(), fi.Name, false));
}
return enumValues;
}
public static T Parse(string value)
{
return (T)Enum.Parse(typeof(T), value, true);
}
public static IList<string> GetNames(Enum value)
{
return value.GetType().GetFields(BindingFlags.Static | BindingFlags.Public).Select(fi => fi.Name).ToList();
}
public static IList<string> GetDisplayValues(Enum value)
{
return GetNames(value).Select(obj => GetDisplayValue(Parse(obj))).ToList();
}
private static string lookupResource(Type resourceManagerProvider, string resourceKey)
{
var resourceKeyProperty = resourceManagerProvider.GetProperty(resourceKey,
BindingFlags.Static | BindingFlags.Public, null, typeof(string),
new Type[0], null);
if (resourceKeyProperty != null)
{
return (string)resourceKeyProperty.GetMethod.Invoke(null, null);
}
return resourceKey; // Fallback with the key name
}
public static string GetDisplayValue(T value)
{
var fieldInfo = value.GetType().GetField(value.ToString());
var descriptionAttributes = fieldInfo.GetCustomAttributes(
typeof(DisplayAttribute), false) as DisplayAttribute[];
if (descriptionAttributes[0].ResourceType != null)
return lookupResource(descriptionAttributes[0].ResourceType, descriptionAttributes[0].Name);
if (descriptionAttributes == null) return string.Empty;
return (descriptionAttributes.Length > 0) ? descriptionAttributes[0].Name : value.ToString();
}
}
然后你可以在视图中使用它,如下所示:
<ul>
@foreach (var value in @EnumHelper<UserPromotion>.GetValues(UserPromotion.None))
{
if (value == Model.JobSeeker.Promotion)
{
var description = EnumHelper<UserPromotion>.GetDisplayValue(value);
<li>@Html.DisplayFor(e => description )</li>
}
}
</ul>