单选按钮列表枚举的MVC 3帮助器
单选按钮列表枚举的MVC 3帮助器
提问于 2012-07-16 22:35:20
我需要些帮助。我正在尝试构建一个视图，其中我需要一组枚举类型的单选按钮。我有几个类似的枚举类型(类)：
[DataContract(Namespace = Constants.SomeDataContractNamespace)]
public enum OneEnumDataContract
{
[Display(Name = "Text_None", Description = "Text_None", ResourceType = typeof(TextResource))]
[EnumMember]
None = 0,
[Display(Name = "Text_Medium", Description = "Text_Medium", ResourceType = typeof(TextResource))]
[EnumMember]
Medium = 1,
[Display(Name = "Text_Very", Description = "Text_Very", ResourceType = typeof(TextResource))]
[EnumMember]
Very = 2
}在我的模型(使用WCF的数据契约)中，我对枚举数据契约有以下属性：
[DataMember(Order = 23)]
[Display(Name = "EnumValue", Description = "EnumValue_Description", ResourceType = typeof(TextResource))]
public OneEnumDataContract EnumClass1 { get; set; }在我看来，我会试着让这组单选按钮像这样(用一个助手)：
@Html.RadioButtonListEnum("EnumList1", Model.EnumClass1)我的助手：
public static MvcHtmlString RadioButtonListEnum<TModel>(this HtmlHelper<TModel> helper, string NameOfList, object RadioOptions)
{
StringBuilder sb = new StringBuilder();
//som other code for pairing with resourcefile...
foreach(var myOption in enumTexts.AllKeys)
{
sb.Append("<p>");
sb.Append(enumTexts.GetValues(myOption)[0]);
sb.Append(helper.RadioButton(NameOfList, System.Convert.ToInt16(myOption)));
sb.Append("</p>");
}
return MvcHtmlString.Create(sb.ToString());
}这为我提供了OneEnumDataContract中的第一个枚举值None，作为参数RadioOptions。如何将数据契约中的所有枚举值都放到帮助器中？
回答 2
Stack Overflow用户
回答已采纳
发布于 2012-07-17 02:56:24
这是我最近创建的一个。如果您在非枚举上尝试它，它将不起作用，但可以满足我的枚举需求。我从不同的DropDownList助手中复制了一些比特和片段，比如nikeaa posted。
#region RadioButtonList
public static MvcHtmlString RadioButtonListFor<TModel, TProperty>(this HtmlHelper<TModel> htmlHelper, Expression<Func<TModel, TProperty>> expression, IDictionary<string, object> htmlAttributes = null) where TModel : class
{
ModelMetadata metadata = ModelMetadata.FromLambdaExpression(expression, htmlHelper.ViewData);
String field = ExpressionHelper.GetExpressionText(expression);
String fieldname = htmlHelper.ViewContext.ViewData.TemplateInfo.GetFullHtmlFieldId(field);
var inputName = fieldname;
TProperty val = GetValue(htmlHelper, expression);
var divTag = new TagBuilder("div");
divTag.MergeAttribute("id", inputName);
divTag.MergeAttribute("class", "radio");
foreach (var item in Enum.GetValues(val.GetType()))
{
DisplayAttribute[] attr = (DisplayAttribute[])item.GetType().GetField(item.ToString()).GetCustomAttributes(typeof(DisplayAttribute), true);
if (attr == null || attr.Length == 0 || attr[0].Name != null)
{
string name = attr != null && attr.Length > 0 && !string.IsNullOrWhiteSpace(attr[0].Name) ? attr[0].Name : item.ToString();
var itemval = item;
var radioButtonTag = RadioButton(htmlHelper, inputName, new SelectListItem { Text = name, Value = itemval.ToString(), Selected = val.Equals(itemval) }, htmlAttributes);
divTag.InnerHtml += radioButtonTag;
}
}
return new MvcHtmlString(divTag.ToString());
}
public static string RadioButton(this HtmlHelper htmlHelper, string name, SelectListItem listItem,
IDictionary<string, object> htmlAttributes)
{
var inputIdSb = new StringBuilder();
inputIdSb.Append(name)
.Append("_")
.Append(listItem.Value);
var sb = new StringBuilder();
var builder = new TagBuilder("input");
if (listItem.Selected) builder.MergeAttribute("checked", "checked");
builder.MergeAttribute("type", "radio");
builder.MergeAttribute("value", listItem.Value);
builder.MergeAttribute("id", inputIdSb.ToString());
builder.MergeAttribute("name", name);
builder.MergeAttributes(htmlAttributes);
sb.Append(builder.ToString(TagRenderMode.SelfClosing));
sb.Append(RadioButtonLabel(inputIdSb.ToString(), listItem.Text, htmlAttributes));
sb.Append("<br>");
return sb.ToString();
}
public static string RadioButtonLabel(string inputId, string displayText,
IDictionary<string, object> htmlAttributes)
{
var labelBuilder = new TagBuilder("label");
labelBuilder.MergeAttribute("for", inputId);
labelBuilder.MergeAttributes(htmlAttributes);
labelBuilder.InnerHtml = displayText;
return labelBuilder.ToString(TagRenderMode.Normal);
}
public static TProperty GetValue<TModel, TProperty>(HtmlHelper<TModel> htmlHelper, Expression<Func<TModel, TProperty>> expression) where TModel : class
{
TModel model = htmlHelper.ViewData.Model;
if (model == null)
{
return default(TProperty);
}
Func<TModel, TProperty> func = expression.Compile();
return func(model);
}
#endregion我是这样使用它的
@Html.RadioButtonListFor(m => m.PlayFormat)对于更复杂的用途，您可能需要更多代码来设置正确的元素名称。
如果枚举项具有Display属性，则显示名称。否则将显示枚举项。如果显示名称为null，则该值不会显示为选项。在这个枚举中，"None“不显示，"Singles”从枚举值中显示，“男人双打”和所有其他的显示文本(Name=“男人双打”)
public enum PlayFormat
{
[Display(Name=null)]
None = 0,
Singles = 1,
[Display(Name = "Men's Doubles")]
MenDoubles = 2,
[Display(Name = "Women's Doubles")]
WomenDoubles = 3,
[Display(Name = "Mixed Doubles")]
MixedDoubles = 4,
[Display(Name = "Men's Group")]
MenGroup = 5,
[Display(Name = "Women's Group")]
WomenGroup = 6,
[Display(Name = "Mixed Group")]
MixedGroup = 7
}页面看起来像这样(除了每个-是一个单选按钮)
- Singles
- Men's Doubles
- Women's Doubles
- Mixed Doubles
- Men's Group
- Women's Group
- Mixed GroupStack Overflow用户
发布于 2012-07-16 22:52:01
这是我在互联网上找到的一个帮助器方法，它可以从枚举中创建一个下拉列表。您应该能够修改此代码以创建单选按钮，而不是下拉列表。
namespace Localicy.HtmlHelpers {
public static class HtmlHelperExtensions {
private static Type GetNonNullableModelType(ModelMetadata modelMetadata) {
Type realModelType = modelMetadata.ModelType;
Type underlyingType = Nullable.GetUnderlyingType(realModelType);
if (underlyingType != null)
realModelType = underlyingType;
return realModelType;
}
private static readonly SelectListItem[] SingleEmptyItem = new[] { new SelectListItem { Text = "", Value = "" } };
public static string GetEnumDescription<TEnum>(TEnum value) {
FieldInfo fi = value.GetType().GetField(value.ToString());
DescriptionAttribute[] attributes = (DescriptionAttribute[])fi.GetCustomAttributes(typeof(DescriptionAttribute), false);
if ((attributes != null) && (attributes.Length > 0))
return attributes[0].Description;
else
return value.ToString();
}
public static MvcHtmlString EnumDropDownListFor<TModel, TEnum>(this HtmlHelper<TModel> htmlHelper, Expression<Func<TModel, TEnum>> expression) {
return EnumDropDownListFor(htmlHelper, expression, null, null);
}
public static MvcHtmlString EnumDropDownListFor<TModel, TEnum>(this HtmlHelper<TModel> htmlHelper, Expression<Func<TModel, TEnum>> expression, string defaultValueText) {
return EnumDropDownListFor(htmlHelper, expression, defaultValueText, null);
}
public static MvcHtmlString EnumDropDownListFor<TModel, TEnum>(this HtmlHelper<TModel> htmlHelper, Expression<Func<TModel, TEnum>> expression, string defaultValueText, object htmlAttributes) {
ModelMetadata metadata = ModelMetadata.FromLambdaExpression(expression, htmlHelper.ViewData);
Type enumType = GetNonNullableModelType(metadata);
IEnumerable<TEnum> values = Enum.GetValues(enumType).Cast<TEnum>();
IEnumerable<SelectListItem> items = from value in values
select new SelectListItem {
Text = GetEnumDescription(value),
Value = value.ToString(),
Selected = value.Equals(metadata.Model)
};
// If the enum is nullable, add an 'empty' item to the collection
if (metadata.IsNullableValueType || defaultValueText != null)
if(defaultValueText != null) {
SelectListItem[] tempItem = new[] { new SelectListItem { Text = defaultValueText, Value = "" } };
items = tempItem.Concat(items);
}
else
items = SingleEmptyItem.Concat(items);
//items = (new ).Concat(items)
return htmlHelper.DropDownListFor(expression, items, htmlAttributes);
}
}
}页面原文内容由Stack Overflow提供。腾讯云小微IT领域专用引擎提供翻译支持
原文链接：
https://stackoverflow.com/questions/11506570
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