Question

我在View

中有一个下拉列表

@Html.DropDownList("GenderAllowed", (SelectList)ViewBag.LocGenederAllowedList, new { @class = "form-control" })

我正在通过ViewBag发送下拉列表，并通过模型发送需要在下拉列表中选择的值。

但是未选择下拉列表中的值。

我的控制器

[HttpGet]
    public ActionResult EditVendorLocation(int VendorLocationID)
    {
        VendorLocationHandler obj = new VendorLocationHandler();
        LocationGrid objLoc = new LocationGrid();
        FillGenederAllowed(objLoc);
        objLoc = obj.GetVendorLocationForAdmin(VendorLocationID);

        return View(objLoc);
    }

Viewbag的功能

public void FillGenederAllowed(LocationGrid V)
{
    Dictionary<int, string> LocGenederAllowed = EnumHelper.GetGenderStates();
    SelectList LocGenederAllowedList = new SelectList(LocGenederAllowed, "key", "value");
    ViewBag.LocGenederAllowedList = LocGenederAllowedList;
}

Answer 1

您传递给DropDownList的SelectListItems具有属性Selected。在ViewModel中，对于最初应选择的项目，将其设置为true。

Answer 2

您可以在控制器操作中执行此操作，如下所示。希望它有所帮助。

ViewBag.LocGenederAllowedList = new SelectList(items, "Id", "Name", selectedValue);

点网小提琴链接：https://dotnetfiddle.net/PFlqei

Answer 3

看看this课程。您需要做的就是创建它们的实例，并为最初要选择的项目将Selected属性设置为true：

public ActionResult YourActionMethod(...)
{
    var selectItems = Repository.SomeDomainModelObjectCollection
      .Select(x => new SelectListItem {
        Text = x.SomeProperty,
        Value = x.SomeOtherProperty,
        Selected = ShoudBeSelected(x)
    });
    ViewBag.SelectListItems = selectItems;
    // more code
    var model = ...; // create your model
    return View(model);
}

您需要Html.DropDownListFor(...)的重叠才能使用this。

Answer 4

你需要在控制器中使用它

   ViewBag.LocGenederAllowedList = 
       new SelectList(db.SomeValues, "Value", "Text",selectedValue);

在你看来

            @Html.DropDownList("GenderAllowed", 
         (SelectList)ViewBag.LocGenederAllowedList, new { @class = "form-control" })

如何在dropdownlist mvc中设置所选值

4 个答案: