枚举绑定使用下拉列表，并在MVC C＃获取动作设定选择的值 [英] Bind Enum with dropdown and set selected value on get action in MVC C#

问题描述

我有一个枚举叫做CityType

I have a Enum called CityType

public enum CityType
    {
        [Description("Select City")]
        Select = 0,

        [Description("A")]
        NewDelhi = 1,

        [Description("B")]
        Mumbai = 2,

        [Description("C")]
        Bangalore = 3,

        [Description("D")]
        Buxar = 4,

        [Description("E")]
        Jabalpur = 5
    }

结果
 从枚举生成列表

  IList<SelectListItem> list = Enum.GetValues(typeof(CityType)).Cast<CityType>().Select(x =>    new SelectListItem(){ 
    Text = EnumHelper.GetDescription(x), 
    Value = ((int)x).ToString()
}).ToList(); 

    int city=0; 
    if (userModel.HomeCity != null) city= (int)userModel.HomeCity;

计算机[HomeCity] =新的SelectList（列表中，值，文本，市）;

ViewData["HomeCity"] = new SelectList(list, "Value", "Text", city);

在绑定.cshtml

 @Html.DropDownList("HomeCity",null,new { @style = "width:155px;", @class = "form-control" })

EnumHelper GetDescription类来获得枚举的说明

EnumHelper GetDescription Class to get Description of Enum

推荐答案

这是code我使用的下拉菜单枚举。
然后，只需使用@ Html.DropDown /对（）;并把这个的SelectList作为参数。<​​/ P>

This is the code I use for enums in dropdowns. Then just use @Html.DropDown/For(); and put this SelectList in as param.

public static SelectList ToSelectList(this Type enumType, string selectedValue)
    {
        var items = new List<SelectListItem>();
        var selectedValueId = 0;
        foreach (var item in Enum.GetValues(enumType))
        {
            FieldInfo fi = enumType.GetField(item.ToString());
            DescriptionAttribute[] attributes = (DescriptionAttribute[])fi.GetCustomAttributes(typeof(DescriptionAttribute), false);
            var title = "";
            if (attributes != null && attributes.Length > 0)
            {
                title = attributes[0].Description;
            }
            else
            {
                title = item.ToString();
            }

            var listItem = new SelectListItem
            {
                Value = ((int)item).ToString(),
                Text = title,
                Selected = selectedValue == ((int)item).ToString(),
            };
            items.Add(listItem);
        }

        return new SelectList(items, "Value", "Text", selectedValueId);
    }

您也可以延长DropDownFor是这样的：

Also you can extend DropDownFor like this:

public static MvcHtmlString EnumDropdownListFor<TModel, TProperty>(this HtmlHelper<TModel> htmlHelper, Expression<Func<TModel, TProperty>> expression, Type enumType, object htmlAttributes = null)
    {
        ModelMetadata metadata = ModelMetadata.FromLambdaExpression(expression, htmlHelper.ViewData);

        SelectList selectList = enumType.ToSelectList(metadata.Model.ToString());

        return htmlHelper.DropDownListFor(expression, selectList, htmlAttributes);
    }

用法那么看起来是这样的：

Usage then looks like this:

@Html.EnumDropdownListFor(model => model.Property, typeof(SpecificEnum))

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