Question

我将此DropDownListFor添加到我的（部分）视图 _CreateUser.cshtml 中：

<div class="modal fade bs-example-modal-lg" id="createUserModal" tabindex="-1" role="dialog" aria-labelledby="myModalLabel" aria-hidden="true">
<div class="modal-dialog">
<div class="modal-content">
    <div class="modal-header">
        <button type="button" class="close" data-dismiss="modal" aria-hidden="true">&times;</button>
        <h4 class="modal-title">Create A User</h4>
    </div>
    @using (Html.BeginForm("Create", "Users", FormMethod.Post))
    {
        <div class="modal-body">

            @Html.LabelFor(model => model.Departments)
            <div>
                @Html.DropDownListFor(
                model => model.SelectedDepartmentIds,
                new SelectList(Model.DepartmentSelectList, "Value", "Text"),
                new {@class = "multiselect departments", multiple = "multiple"})
            </div>
        ...

以上部分视图在主视图 Index.cshtml 中声明，并在点击＆＃39;创建＆＃39;时显示为模式弹出窗口。按钮

@Html.ActionLink("Create user", "Create", "Users", new { @class = "btn btn-primary", @href = "#createUserModal", @data_toggle="modal" })    
...    
@Html.Partial("_CreateUser", new UserViewModel()
             {   //Populating SelectList required for loading dropdownlist
                 DepartmentSelectList = modelFactory != null ? 
                                        modelFactory.Departments.Select(dept => new SelectListItem{Value = dept.Id.ToString(),Text = dept.Name}).ToList() 
                                        : null
             })

UserViewModel.cs

public IEnumerable<String> Departments { get; set; }
//Used purely for binding DropDownList
public IEnumerable<SelectListItem> DepartmentSelectList { get; set; } 
public string SelectedDepartmentIds { get; set; }
//Ideally, I want to populate selected items in this list
public IEnumerable<DepartmentModel> DepartmentModels { get; set; }

UserController.cs

[HttpPost]
public ActionResult Create(UserViewModel postedModel)
{
        if (ModelState.IsValid)
        {
            //Incorrect - returns only first selected Id
            string selectedIds = postedModel.SelectedDepartmentIds;

            //Correct - returns correct selected Ids
            string selectedIds1 = ModelState["SelectedDepartmentId"].Value.AttemptedValue;
            ...
            ...

两个问题：

如何从DropDownList中检索所有选定的项目，作为模型属性的一部分＆＃34; SelectedDepartmentId＆＃34;？我是否需要在运行时使用jQuery更新ModalProperty？

我可以设置我的视图以便绑定Modal属性＆＃34; DepartmentModels＆＃34;使用DropDownList - 它将帮助我检索所选项目的完整对象？目前，如果我尝试这样做，我会收到此错误：
{＆＃34;参数转换类型＆＃39; System.String＆＃39;键入＆＃39; ... DepartmentModel＆＃39;失败，因为没有类型转换器可以在这些类型之间进行转换。＆＃34;}

谢谢！

Answer 1

在查看各种Google搜索后得到了解决:-)

下面是正确加载和返回所选对象的代码 -

<强>型号：

public class UserGroupViewModel
{
    public IEnumerable<SelectListItem> GroupSelectList
    {
        get
        {
            List<Group> groups = new List<Group>
                {
                    new Group() {Id = 1, Name = "AA"},
                    new Group() {Id = 2, Name = "BB"},
                    new Group() {Id = 3, Name = "CC"}
                };
            IEnumerable<SelectListItem> groupsSelectList = groups.Select(group => new SelectListItem                                                                          {   Text = group.Name, Value = group.Id.ToString(), Selected = group.Id == 2}).ToList();
            return groupsSelectList;
        }
    }

    [Required]
    [Display(Name = "Group")]
    public int[] SelectedGroupIds { get; set; }
}

查看：

<div class="form-group"> @Html.LabelFor(model => model.SelectedGroupIds, new { @class = "control-label col-md-2" }) <div class="col-md-10"> @Html.DropDownListFor(model => model.SelectedGroupIds, Model.GroupSelectList, new { @class = "multiselect", multiple = "multiple" }) @Html.ValidationMessageFor(model => model.SelectedGroupIds) </div> </div>

要在表单加载时将某些项目显示为“已选择”，只需将SelectListItem的“Selected”属性设置为true即可。

HTH。

返回MultiSelect DropDownList的所选对象

1 个答案: