在ASP.NEt MVC 3中的Html.BeginForm()中传递DropDownList的SelectedValue

Question

这是我的查看代码:

@using(Html.BeginForm(new { SelectedId = /*SelectedValue of DropDown*/ })) {

 <fieldset>

     <dl>
       <dt>
           @Html.Label(Model.Category)
       </dt>
       <dd>
        @Html.DropDownListFor(model => Model.Category, CategoryList)
       </dd>
    </dl>

 </fieldset>
 <input type="submit" value="Search" />


}

如图所示,我需要将dropdown所选值传递给BeginForm()Html帮助器中的操作.你的建议是什么？

Answer 1

提交表单时将传递选定的值,因为下拉列表由<select>元素表示.您只需调整视图模型,以便它具有一个属性SelectedId,例如,您将绑定下拉列表:

@using(Html.BeginForm() )
{
    <fieldset>
        <dl>
            <dt>
                @Html.LabelFor(x => x.SelectedId)
            </dt>
           <dd>
                @Html.DropDownListFor(x => x.SelectedId, Model.CategoryList)
           </dd>
        </dl>
    </fieldset>

    <input type="submit" value="Search" />
}

这假定以下视图模型:

public class MyViewModel
{
    [DisplayName("Select a category")]
    public int SelectedId { get; set; }

    public IEnumerable<SelectListItem> CategoryList { get; set; }
}

这将由您的控制器处理:

public ActionResult Index()
{
    var model = new MyViewModel();
    // TODO: this list probably comes from a repository or something
    model.CategoryList = new[]
    {
        new SelectListItem { Value = "1", Text = "category 1" },
        new SelectListItem { Value = "2", Text = "category 2" },
        new SelectListItem { Value = "3", Text = "category 3" },
    };
    return View(model);
}

[HttpPost]
public ActionResult Index(MyViewModel model)
{
    // here you will get the selected category id in model.SelectedId
    return Content("Thanks for selecting category id: " + model.SelectedId);
}