我想知道是否有人可以解决这个问题。
我有一个选项组下拉列表用于选择一个人的种族 - 但是它没有将该值存储在模型中。
视图模型
[UIHint("EthnicOriginEditorTemplate")]
[DisplayName("Question 6: Ethnic Origin")]
public int EthnicOrigin { get; set; }
Helper:GroupDropList.Cs
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Web.Mvc;
using System.Web.Routing;
namespace Public.Helpers
{
public static class GroupDropListExtensions
{
public static string GroupDropList(this HtmlHelper helper, string name, IEnumerable<GroupDropListItem> data, int SelectedValue, object htmlAttributes)
{
if (data == null && helper.ViewData != null)
data = helper.ViewData.Eval(name) as IEnumerable<GroupDropListItem>;
if (data == null) return string.Empty;
var select = new TagBuilder("select");
if (htmlAttributes != null)
select.MergeAttributes(new RouteValueDictionary(htmlAttributes));
select.GenerateId(name);
var optgroupHtml = new StringBuilder();
var groups = data.ToList();
foreach (var group in data)
{
var groupTag = new TagBuilder("optgroup");
groupTag.Attributes.Add("label", helper.Encode(group.Name));
var optHtml = new StringBuilder();
foreach (var item in group.Items)
{
var option = new TagBuilder("option");
option.Attributes.Add("value", helper.Encode(item.Value));
if (SelectedValue != 0 && item.Value == SelectedValue)
option.Attributes.Add("selected", "selected");
option.InnerHtml = helper.Encode(item.Text);
optHtml.AppendLine(option.ToString(TagRenderMode.Normal));
}
groupTag.InnerHtml = optHtml.ToString();
optgroupHtml.AppendLine(groupTag.ToString(TagRenderMode.Normal));
}
select.InnerHtml = optgroupHtml.ToString();
return select.ToString(TagRenderMode.Normal);
}
}
public class GroupDropListItem
{
public string Name { get; set; }
public List<OptionItem> Items { get; set; }
}
public class OptionItem
{
public string Text { get; set; }
public int Value { get; set; }
}
}
这是我的EditorTemplate
<%@ Import Namespace="Public.Helpers"%>
<%@ Control Language="C#" Inherits="System.Web.Mvc.ViewUserControl<int>"%>
<%=Html.GroupDropList("EthnicOrigin",
new[]
{
new GroupDropListItem
{
Name = "Ethnicity",
Items = new List<OptionItem>
{
new OptionItem {Value = 0, Text = "Please Select"}
}
},
new GroupDropListItem
{
Name = "a) White",
Items = new List<OptionItem>
{
new OptionItem {Value = 1, Text = "British"},
new OptionItem {Value = 2, Text = "Irish"},
new OptionItem {Value = 3, Text = "Other White (Please specify below)"}
}
},
--snip
}, Model, null)%>
在视图中我将其引用为:
<%=Html.EditorFor(x => x.EthnicOrigin, "EthnicOriginEditorTemplate")%>
然而,它没有通过选定的值传递到模型中...有任何人遇到过类似的问题......非常感谢提前做了一些指示。
答案 0 :(得分:8)
您的select
没有name
属性,因此当您提交表单时,所选值不会发送到服务器。您需要添加名称:
select.GenerateId(name);
select.MergeAttribute("name", name);
答案 1 :(得分:5)
刚刚更改了助手类,使其适用于MVC 3和nullable int。 非常感谢上课,节省了我很多时间。
public static class GroupDropListExtensions
{
public static MvcHtmlString GroupDropList(this HtmlHelper helper, string name, IEnumerable<GroupDropListItem> data, int? SelectedValue, object htmlAttributes)
{
if (data == null && helper.ViewData != null)
data = helper.ViewData.Eval(name) as IEnumerable<GroupDropListItem>;
if (data == null) return new MvcHtmlString(string.Empty);
var select = new TagBuilder("select");
if (htmlAttributes != null)
select.MergeAttributes(new RouteValueDictionary(htmlAttributes));
select.GenerateId(name);
select.MergeAttribute("name", name);
var optgroupHtml = new StringBuilder();
var groups = data.ToList();
foreach (var group in data)
{
var groupTag = new TagBuilder("optgroup");
groupTag.Attributes.Add("label", helper.Encode(group.Name));
var optHtml = new StringBuilder();
foreach (var item in group.Items)
{
var option = new TagBuilder("option");
option.Attributes.Add("value", helper.Encode(item.Value));
if (SelectedValue != 0 && item.Value == SelectedValue)
option.Attributes.Add("selected", "selected");
option.InnerHtml = helper.Encode(item.Text);
optHtml.AppendLine(option.ToString(TagRenderMode.Normal));
}
groupTag.InnerHtml = optHtml.ToString();
optgroupHtml.AppendLine(groupTag.ToString(TagRenderMode.Normal));
}
select.InnerHtml = optgroupHtml.ToString();
return new MvcHtmlString(select.ToString(TagRenderMode.Normal));
}
}
public class GroupDropListItem
{
public string Name { get; set; }
public List<OptionItem> Items { get; set; }
}
public class OptionItem
{
public string Text { get; set; }
public int Value { get; set; }
}
答案 2 :(得分:1)
从ASP.NET MVC 5.2开始,本机支持使用SelectListGroup:
var items = new List<SelectListItem>();
var group1 = new SelectListGroup() { Name = "Group 1" };
items.Add(new SelectListItem() { Text = "Item1", Group = group1 });
然后在MVC中,执行
@Html.DropDownList("select", items)