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>

当前回答

你需要使用一些反射来访问该属性:

var type = typeof(UserPromotion);
var member = type.GetMember(Model.JobSeeker.Promotion.ToString());
var attributes = member[0].GetCustomAttributes(typeof(DisplayAttribute), false);
var name = ((DisplayAttribute)attributes[0]).Name;

我建议将此方法包装在扩展方法中,或者在视图模型中执行此操作。

其他回答

从上面将所有边情况组合在一起:

枚举包含基对象成员名的成员(Equals, ToString) 可选显示属性

这是我的代码:

public enum Enum
{
    [Display(Name = "What a weird name!")]
    ToString,

    Equals
}

public static class EnumHelpers
{
    public static string GetDisplayName(this Enum enumValue)
    {
        var enumType = enumValue.GetType();

        return enumType
                .GetMember(enumValue.ToString())
                .Where(x => x.MemberType == MemberTypes.Field && ((FieldInfo)x).FieldType == enumType)
                .First()
                .GetCustomAttribute<DisplayAttribute>()?.Name ?? enumValue.ToString();
    }
}

void Main()
{
    Assert.Equals("What a weird name!", Enum.ToString.GetDisplayName());
    Assert.Equals("Equals", Enum.Equals.GetDisplayName());
}

有了Core 2.1,

public static string GetDisplayName(Enum enumValue)
{
  return enumValue.GetType()?
 .GetMember(enumValue.ToString())?[0]?
 .GetCustomAttribute<DisplayAttribute>()?
 .Name;
}

我想贡献与区域性相关的GetDisplayName enum扩展。希望这对以前像我一样在谷歌上搜索这个答案的人有用:

Aydin Adn和Todd提到的“标准”方式:

    public static string GetDisplayName(this Enum enumValue)
    {
        return enumValue
            .GetType()
            .GetMember(enumValue.ToString())
            .First()
            .GetCustomAttribute<DisplayAttribute>()
            .GetName();
    }

“文化相关的”方式:

    public static string GetDisplayName(this Enum enumValue, CultureInfo ci)
    {
        var displayAttr = enumValue
            .GetType()
            .GetMember(enumValue.ToString())
            .First()
            .GetCustomAttribute<DisplayAttribute>();

        var resMan = displayAttr.ResourceType?.GetProperty(@"ResourceManager", BindingFlags.Static | BindingFlags.Public | BindingFlags.NonPublic).GetValue(null, null) as ResourceManager;

        return resMan?.GetString(displayAttr.Name, ci) ?? displayAttr.GetName();
    }
<ul>
    @foreach (int aPromotion in @Enum.GetValues(typeof(UserPromotion)))
    {
        var currentPromotion = (int)Model.JobSeeker.Promotion;
        if ((currentPromotion & aPromotion) == aPromotion)
        {
        <li>@Html.DisplayFor(e => currentPromotion)</li>
        }
    }
</ul>

为了显示枚举的display name属性,只需使用 Microsoft.AspNetCore.Mvc.Rendering的

@Html.DisplayFor(x => EnumType.EnumValue)

这就足够了。

要显示SelectList,写如下:

 <select id="someIdForTheEndPoint" asp-items="Html.GetEnumSelectList<EnumType>()">
     <option selected="selected" value="">Select value</option>
 </select>