c# - 在我的 MVC3 的下拉列表中禁用一个项目

Question

我有一个 MVC3 应用程序。我想根据条件禁用特定项目dropdown list。

@Html.DropDownList("ReportName", Model.ReportTypes, new { style = "color:black; float:left; padding:5px;", @id = "ReportType" })
         @if (Model.numCount > 500)
         { 
          // disable the item whose value = "RC-Report";
         }

Answer 1

填充 SelectListItemExtends 列表，并传递给 ViewBag：

ViewBag.List = new Biz().ListSmall()
                .Select(s => new SelectListItemExtends()
                {
                    Text = s.dsc,
                    Value = s.id,
                    Enabled = s.is_active
                }).ToArray();

在您看来使用：

@Html.DropDownList("id", ViewBag.List as IEnumerable<SelectListItemExtends>, new { })

创建文件 HtmlHelperExtensions.cs：

using System.Collections.Generic;
using System.Web.Routing;

namespace System.Web.Mvc.Html
{
    public static class HtmlHelperExtensions
    {
        public static MvcHtmlString DropDownList(this HtmlHelper htmlHelper, string name, IEnumerable<SelectListItemExtends> selectList, object htmlAttributes)//, Func<object, bool> ItemDisabled)
        {
            //Creating a select element using TagBuilder class which will create a dropdown.
            TagBuilder dropdown = new TagBuilder("select");
            //Setting the name and id attribute with name parameter passed to this method.
            dropdown.Attributes.Add("name", name);
            dropdown.Attributes.Add("id", name);

            var options = "";
            TagBuilder option;
            //Iterated over the IEnumerable list.
            foreach (var item in selectList)
            {
                option = new TagBuilder("option");
                option.MergeAttribute("value", item.Value.ToString());

                if (item.Enabled == false)
                    option.MergeAttribute("disabled", "disabled");

                if (item.PropExtends != null)
                    option.MergeAttributes(item.PropExtends);

                option.SetInnerText(item.Text);
                options += option.ToString(TagRenderMode.Normal) + "\n";
            }
            //assigned all the options to the dropdown using innerHTML property.
            dropdown.InnerHtml = options.ToString();
            //Assigning the attributes passed as a htmlAttributes object.
            dropdown.MergeAttributes(new RouteValueDictionary(htmlAttributes));
            //Returning the entire select or dropdown control in HTMLString format.
            return MvcHtmlString.Create(dropdown.ToString(TagRenderMode.Normal));

        }
    }
    public class SelectListItemExtends : SelectListItem
    {
        public bool Enabled { get; set; }
        public IDictionary<string, string> PropExtends { get; set; }
    }
}

结果是：

<select name="id" id="id">
    <option value="430">Object 1</option>
    <option value="5c7" disabled="disabled">Object 2</option>
</select>

攻击者

胡里奥·斯派德

wessolucoes.com.br

Answer 2

使用 jQuery

    <select id="theSelect">
        <option value="1">1</option>
        <option value="2">2</option>
        <option value="3">3</option>
        <option value="500">500</option>
    </select>
    <script type="text/javascript">
    $(function () {
        $('#theSelect option[value=500]').each(function (i, item) {
            item.disabled = true;
        });
    });
</script>

---

更新

多个值

    <script type="text/javascript">
    $(function () {
        $('#theSelect option').each(function (i, item) {
          var itemValue = $(item).va();
          if(itemValue == '500' || itemValue == '500_1' || itemValue == '500-1')
            item.disabled = true;
        });
    });
</script>

Answer 3

如果您想在剃刀本身中执行此操作，则在条件期间只需构建属性并在 DropDownListConstructor 中分​​配它。

  @{

      IDictionary<string, object> attributes = 
         new RouteValueDictionary(
            new { 
       style =  "color:black; float:left; padding:5px;", 
       @id = "ReportType"
     });

     if (Model.numCount > 500)
     { 
      // disable the item whose value = "RC-Report";
         attributes.Add("disabled", "disabled");
     }

  }
 @Html.DropDownList("ReportName", Model.ReportTypes, attributes);

Answer 4

回到经典：

<select style="color:black; float:left; padding:5px;" id="ReportType">
                    <%foreach(var type in Model.ReportTypes) {%>
                     <option value="<%=type.Property%>"
                        <%if(Model.numCount > 500) {%>
                            <%if(Model.Name=="RC-Report") {%>
                            disabled="disabled"
                        <%}%>
                        <%}%>
                      > <%=type.Name%>
                    </option>
                    <%}%>
                  </select>