Question

默认情况下，我无法选择下拉列表。

模特的标题属性先生。但下拉列表不会选择它。

CSHTML -

@Html.TextBoxFor(model=>model.Title)
@Html.DropDownListFor(model => model.Title, @ViewBag.All_Title as SelectList, new { @class = "form-control" })

CS代码 -

ViewBag.All_Title = Titles(model.Title);

标题方法 -

public static SelectList Titles(string selectedValue)
    {
        List<SelectListItem> titles = new List<SelectListItem>();

        titles.Add(new SelectListItem { Text = "Prof.", Value = "Prof." });
        titles.Add(new SelectListItem { Text = "Dr.", Value = "Dr." });
        titles.Add(new SelectListItem { Text = "Miss", Value = "Miss" });
        titles.Add(new SelectListItem { Text = "Mr.", Value = "Mr." });
        titles.Add(new SelectListItem { Text = "Mrs.", Value = "Mrs." });
        titles.Add(new SelectListItem { Text = "Ms.", Value = "Ms." });

        SelectList sl = new SelectList(titles, "Value", "Text");//, selectedValue);
        return sl;
    }

模型是 -

[Required]
[Display(Name = "Title")]
public string Title { get; set; }
public SelectList All_Title { get; set; }

更新

调试器显示先生＆＃39;是selectedValue但它不会在网页上保持选中状态。

Answer 1

试试这个：

@Html.DropDownList("All_Title", null, htmlAttributes: new { @class = "form-control" })

更新

您需要在模型中保留所选的项目ID：

标题方法：

public static SelectList Titles(string selectedValue)
{
    List<SelectListItem> titles = new List<SelectListItem>();

    titles.Add(new SelectListItem { Text = "Prof.", Value = "1" });
    titles.Add(new SelectListItem { Text = "Dr.", Value = "2" });
    titles.Add(new SelectListItem { Text = "Miss.", Value = "3" });
    titles.Add(new SelectListItem { Text = "Mr.", Value = "4" });
    titles.Add(new SelectListItem { Text = "Mrs.", Value = "5" });
    titles.Add(new SelectListItem { Text = "Ms.", Value = "6" });

    SelectList sl = new SelectList(titles, "Value", "Text", selectedValue);
    return sl;
}

<强>型号：

[Required]
[Display(Name = "Title")]
public string Title { get; set; }
public int All_Title_Id { get; set; }

<强>控制器：

ViewBag.All_Title_Id = Titles(model.Title);

查看：

@Html.DropDownList("All_Title_Id", null, htmlAttributes: new { @class = "form-control" })

Answer 2

我们在项目中使用这个。

 @Html.DropDownListFor(model => Model.Client.ID, new SelectList(Model.Clients, "ID", "Name", Model.Client), "- All -", new { @class = "projects-drop-down", @id = "clientListDropDown"})

所以，你的下拉列表应该是这样的

 @Html.DropDownListFor(model => model.Title, new SelectList(ViewBag.All_Title, "Value", "Text", ViewBag.YourSelectListItemProperty), "- Select -", new { @class = "projects-drop-down", @id = "clientListDropDown"})

Answer 3

这是怎么回事？

public static SelectList Titles(string selectedValue)
{
    List<SelectListItem> titles = new List<SelectListItem>();

    titles.Add(new SelectListItem { Text = "Prof.", Value = "Prof." });
    titles.Add(new SelectListItem { Text = "Dr.", Value = "Dr." });
    titles.Add(new SelectListItem { Text = "Miss", Value = "Miss" });
    titles.Add(new SelectListItem { Text = "Mr.", Value = "Mr.", Selected = true });
    titles.Add(new SelectListItem { Text = "Mrs.", Value = "Mrs." });
    titles.Add(new SelectListItem { Text = "Ms.", Value = "Ms." });

    SelectList sl = new SelectList(titles, "Value", "Text");//, selectedValue);
    return sl;
}

无法为DropDownList选择默认值

3 个答案:

更新