Question

我正在为视图使用下拉列表的硬编码字符串值，并从数据库传递选定的值，其中0 =挂起，1 =完成，3 =等待，下面是视图和控制器的代码：

 var paymentStatus = new[] { "Pending", "Complete", "AwaitingPayment" };
  ViewData["StatusID"] = new SelectList(paymentStatus, "Value", "Text", booking.StatusID);


   <tr><td>Status</td><td><%: Html.DropDownListFor(m => m.StatusID, ViewData["StatusID"] as SelectList)%></td></tr>

它出现了错误： DataBinding：'System.String'不包含名为'Value'的属性。

Answer 1

您的示例的问题在于您将字符串数组传递到SelectList，然后告诉SelectList使用Value和Text属性（字符串不具有））。您应该为此创建一个类：

public class Status {
    public int Id { get; set; }
    public string Text { get; set; }
}

var statusTypes = new List<Status> {
    new Status { Id = 1, Text = "Pending" },
    new Status { Id = 2, Text = "Complete" },
    new Status { Id = 3, Text = "AwaitingPayment" }
};

更好的是，为这些数据创建一个存储库：

var statusTypes = statusRepository.GetStatusTypes();

将此传递到您的SelectList：

SelectList statusList = new SelectList(statusTypes, "Id", "Text", booking.StatusID);

// return this in a ViewModel or use ViewData like you are now:
ViewData["Status"] = statusList;

return View(statusList);

Answer 2

请使用视图模型：

var paymentStatuses = new[]
{
    new SelectListItem { Value = "0", Text = "Pending" },
    new SelectListItem { Value = "1", Text = "Complete" },
    new SelectListItem { Value = "3", Text = "AwaitingPayment" },
};
var model = new SomeViewModel
{
    StatusID = booking.StatusID,
    Statuses = new SelectList(paymentStatuses, "Value", "Text")
}
return View(model);

然后：

<tr>
    <td>
        Status
    </td>
    <td>
        <%= Html.DropDownListFor(m => m.StatusID, Model.Statuses) %>
    </td>
</tr>

或者你坚持这个ViewData（我不推荐它，特别是你已经有了一个视图模型）：

var paymentStatuses = new[]
{
    new SelectListItem { Value = "0", Text = "Pending" },
    new SelectListItem { Value = "1", Text = "Complete" },
    new SelectListItem { Value = "3", Text = "AwaitingPayment" },
};
ViewData["Statuses"] = new SelectList(paymentStatuses, "Value", "Text");
var model = new SomeViewModel
{
    StatusID = booking.StatusID
}
return View(model);

并在视图中：

<tr>
    <td>
        Status
    </td>
    <td>
        <%= Html.DropDownListFor(m => m.StatusID, ViewData["Statuses"] as SelectList) %>
    </td>
</tr>

Answer 3

错误显示无法找到“值”，您必须执行类似

的操作

new SelectList(paymentStatus, booking.Status, "Text", booking.StatusID)

booking.Status将是预订的任何文本属性。希望这个帮助

DropdownlistFor会抛出错误

3 个答案: