如何为枚举制作默认的编辑器模板?我的意思是:我可以做这样的事情:
<%@ Control Language="C#" Inherits="System.Web.Mvc.ViewUserControl<Enum>" %>
<% -- any code to read the enum and write a dropdown -->
并将其放在名为Enum.ascx
?
这是我尝试过的问题的解决方法,但这不是我需要的。
这是我的枚举:
public enum GenderEnum
{
/// <summary>
/// Male
/// </summary>
[Description("Male Person")]
Male,
/// <summary>
/// Female
/// </summary>
[Description("Female Person")]
Female
}
我创建了一个名为GenderEnum.acsx
的模板,并将其放在Shared/EditorTemplates
文件夹中。这是模板:
<%@ Control Language="C#" Inherits="System.Web.Mvc.ViewUserControl<AlefTech.HumanResource.Core.GenderEnum>" %>
<%@ Import Namespace="AlefTech.HumanResource.WebModule.Classes" %>
<%=Html.DropDownListFor(m => m.GetType().Name, Model.GetType()) %>
当然这个方法是我自己的:
public static class HtmlHelperExtension
{
public static MvcHtmlString DropDownListFor<TModel, TProperty>(this HtmlHelper<TModel> htmlHelper, Expression<Func<TModel, TProperty>> expression, Type enumType)
{
List<SelectListItem> list = new List<SelectListItem>();
Dictionary<string, string> enumItems = enumType.GetDescription();
foreach (KeyValuePair<string, string> pair in enumItems)
list.Add(new SelectListItem() { Value = pair.Key, Text = pair.Value });
return htmlHelper.DropDownListFor(expression, list);
}
/// <summary>
/// return the items of enum paired with its descrtioption.
/// </summary>
/// <param name="enumeration">enumeration type to be processed.</param>
/// <returns></returns>
public static Dictionary<string, string> GetDescription(this Type enumeration)
{
if (!enumeration.IsEnum)
{
throw new ArgumentException("passed type must be of Enum type", "enumerationValue");
}
Dictionary<string, string> descriptions = new Dictionary<string, string>();
var members = enumeration.GetMembers().Where(m => m.MemberType == MemberTypes.Field);
foreach (MemberInfo member in members)
{
var attrs = member.GetCustomAttributes(typeof(DescriptionAttribute), false);
if (attrs.Count() != 0)
descriptions.Add(member.Name, ((DescriptionAttribute)attrs[0]).Description);
}
return descriptions;
}
}
然而,即使这对我有用,但这不是我所要求的。相反,我需要以下工作:
Shared\EditorTemplates\Enum.acsx
的代码:
<%@ Control Language="C#" Inherits="System.Web.Mvc.ViewUserControl<Enum>" %>
<%@ Import Namespace="System.Web.Mvc.Html" %>
<%@ Import Namespace="WhereMyExtentionMethod" %>
<%=Html.DropDownListFor(m => m.GetType().Name, Model.GetType()) %>
有了这个,我就不用再为每个枚举制作模板了。
答案 0 :(得分:18)
迟到回答,但我希望这有助于其他人。理想情况下,您希望所有枚举按惯例使用您的Enum模板,而不是每次都指定UIHint,您可以通过创建这样的自定义模型元数据提供程序来实现:
using System;
using System.Collections.Generic;
using System.Web.Mvc;
public class CustomMetadataProvider : DataAnnotationsModelMetadataProvider
{
protected override ModelMetadata CreateMetadata(IEnumerable<Attribute> attributes, Type containerType, Func<object> modelAccessor, Type modelType, string propertyName) {
var mm = base.CreateMetadata(attributes, containerType, modelAccessor, modelType, propertyName);
if (modelType.IsEnum && mm.TemplateHint == null) {
mm.TemplateHint = "Enum";
}
return mm;
}
}
然后只需在Global.asax.cs的Application_Start方法中注册它:
ModelMetadataProviders.Current = new CustomMetadataProvider();
现在,默认情况下,所有枚举属性都将使用您的枚举模板。
答案 1 :(得分:7)
谢谢大家的贡献
Yngvebn,我之前尝试过您的解决方案(在您的上次评论中),但我唯一没做的是<dynamic>
,我在泛型中使用了<Enum>
。
最后的解决方案是:
创建一个名为Enum.acsx的模板并将其放在 Views \ Shared \ EditorTemplates
<%@ Control Language="C#" Inherits="System.Web.Mvc.ViewUserControl<dynamic>" %>
<%@ Import Namespace="System.Web.Mvc.Html" %>
<%@ Import Namespace="the extension methods namespace" %>
<% Enum model = (Enum)Model; %>
<%=Html.DropDownList(model.GetType().Name,model.GetType())%>
并在您的实体中:
public class Person
{
[UIHint("Enum")]
public GenderEnum Gender{get;set;}
}
public Enum GenderEnum
{
[Description("Male Person")]
Male,
[Description("Female Person")]
Female
}
并且还有扩展方法:
public static class HtmlHelperExtension
{
public static MvcHtmlString DropDownListFor<TModel, TProperty>(this HtmlHelper<TModel> htmlHelper, Expression<Func<TModel, TProperty>> expression, Type enumType)
{
List<SelectListItem> list = new List<SelectListItem>();
Dictionary<string, string> enumItems = enumType.GetDescription();
foreach (KeyValuePair<string, string> pair in enumItems)
list.Add(new SelectListItem() { Value = pair.Key, Text = pair.Value });
return htmlHelper.DropDownListFor(expression, list);
}
/// <summary>
/// return the items of enum paired with its descrtioption.
/// </summary>
/// <param name="enumeration">enumeration type to be processed.</param>
/// <returns></returns>
public static Dictionary<string, string> GetDescription(this Type enumeration)
{
if (!enumeration.IsEnum)
{
throw new ArgumentException("passed type must be of Enum type", "enumerationValue");
}
Dictionary<string, string> descriptions = new Dictionary<string, string>();
var members = enumeration.GetMembers().Where(m => m.MemberType == MemberTypes.Field);
foreach (MemberInfo member in members)
{
var attrs = member.GetCustomAttributes(typeof(DescriptionAttribute), false);
if (attrs.Count() != 0)
descriptions.Add(member.Name, ((DescriptionAttribute)attrs[0]).Description);
}
return descriptions;
}
}
答案 2 :(得分:5)
这是我为此做的帮手.. 在您的视图中,您可以执行以下操作:
<%= Html.DropDownForEnum<MyEnum>("some-name-for-dropdown", MyEnum.TheFirstValue) %>
对于实际下拉列表中的文本,它将在资源文件中查找与枚举名称匹配的资源,否则只需编写实际的Enumtext本身。
public static MvcHtmlString DropDownForEnum<T>(this HtmlHelper h, string name, T selectedValue)
{
Type enumType = typeof(T);
Tag t = new Tag("select").With("name", name).And("id", name);
foreach (T val in Enum.GetValues(enumType))
{
string enumText = Resources.ResourceManager.GetString(val.ToString());
if (String.IsNullOrEmpty(enumText)) enumText = val.ToString();
Tag option = new Tag("option").With("value", (val).ToString()).AndIf(val.Equals(selectedValue), "selected", "selected").WithText(enumText);
t.Append(option);
}
return MvcHtmlString.Create(t.ToString());
}
如果您希望它不需要重写,您还需要我重载的Tag类。
public class Tag : TagBuilder
{
public Tag (string TagName): base(TagName)
{
}
public Tag Append(Tag innerTag)
{
base.InnerHtml += innerTag.ToString();
return this;
}
public Tag WithText(string text)
{
base.InnerHtml += text;
return this;
}
public Tag With(Tag innerTag)
{
base.InnerHtml = innerTag.ToString();
return this;
}
public Tag With(string attributeName, string attributeValue)
{
base.Attributes.Add(attributeName, attributeValue);
return this;
}
public Tag And(string attributeName, string attributeValue)
{
base.Attributes.Add(attributeName, attributeValue);
return this;
}
public Tag AndIf(bool condition, string attributeName, string attributeValue)
{
if(condition)
base.Attributes.Add(attributeName, attributeValue);
return this;
}
}
答案 3 :(得分:5)
Nour Sabony,我修改了你的版本,也支持使用资源进行本地化。因此,我将DescriptionAttribute更改为DataAnnotations命名空间的DisplayAttribute
public static MvcHtmlString DropDownListFor<TModel, TProperty>(this HtmlHelper<TModel> htmlHelper, Expression<Func<TModel, TProperty>> expression, Type enumType)
{
List<SelectListItem> list = new List<SelectListItem>();
Dictionary<string, string> enumItems = enumType.GetDisplayNames(htmlHelper.ViewContext.HttpContext);
foreach (KeyValuePair<string, string> pair in enumItems)
list.Add(new SelectListItem() { Value = pair.Key, Text = pair.Value });
return htmlHelper.DropDownListFor(expression, list);
}
/// <summary>
/// return the items of enum paired with its DisplayName.
/// </summary>
/// <param name="enumeration">enumeration type to be processed.</param>
/// <returns></returns>
public static Dictionary<string, string> GetDisplayNames(this Type enumeration, HttpContextBase httpContext)
{
if (!enumeration.IsEnum)
{
throw new ArgumentException("passed type must be of Enum type", "enumerationValue");
}
Dictionary<string, string> displayNames = new Dictionary<string, string>();
var members = enumeration.GetMembers().Where(m => m.MemberType == MemberTypes.Field);
foreach (MemberInfo member in members)
{
var attrs = member.GetCustomAttributes(typeof(DisplayAttribute), false);
if (attrs.Count() != 0)
if (((DisplayAttribute)attrs[0]).ResourceType != null)
{
displayNames.Add(member.Name, ((DisplayAttribute)attrs[0]).GetName(););
}
else
{
displayNames.Add(member.Name, ((DisplayAttribute)attrs[0]).Name);
}
}
return displayNames;
}
枚举的定义现在必须如此:
public enum Gender
{
[Display(Name = "Male", ResourceType = typeof(mynamespace.App_LocalResources.Shared))]
Male = 1,
[Display(Name = "Female", ResourceType = typeof(mynamespace.App_LocalResources.Shared))]
Female = 2,
}
它可以以相同的方式在视图中使用,例如(剃刀):
@Html.DropDownListFor(model => model.Gender, typeof(Gender))
希望这有助于某人!
答案 4 :(得分:2)
我使dropdownlistfor方法更容易了,现在你可以给它一个selectedValue:
public static MvcHtmlString DropDownListFor<TModel, TProperty>(this HtmlHelper<TModel> htmlHelper, Expression<Func<TModel, TProperty>> expression, Type enumType)
{
return DropDownListFor(htmlHelper, expression, enumType, null);
}
public static MvcHtmlString DropDownListFor<TModel, TProperty>(this HtmlHelper<TModel> htmlHelper, Expression<Func<TModel, TProperty>> expression, Type enumType, object selectedValue)
{
Dictionary<string, string> enumItems = enumType.GetDisplayNames(htmlHelper.ViewContext.HttpContext);
return htmlHelper.DropDownListFor(expression, new SelectList(enumItems, "Key", "Value", selectedValue));
}
在您的视图中使用它:
@Html.DropDownListFor(m => m.Gender, typeof(Gender), Model.Gender)
Model是我的MVC模型,它的属性Gender包含DropDownListFor的selectedValue。
答案 5 :(得分:1)
我认为没有一种默认方法可以为所有枚举类型定义编辑器,因为根据具体情况,您可能需要不同的行为。例如,你可能有一个[Flags]枚举并想要多选,或者你想要一个下拉列表,或者你想要单选按钮。
另外,通常你会想要某种有意义的显示字符串,超出你在变量命名限制中所能达到的范围。
当然将分配给enum类型的属性是开箱即用的,但是你如何得到这个值将取决于你。
答案 6 :(得分:0)
是
几乎可以肯定这是开箱即用的。
尝试使用与枚举相同的名称命名模板。