清除模型后,为什么文本框不会清除

Question

我有一个通过ajax提交给Controller的表单.Controller从Model收集数据,然后创建一个新的ViewModel并将其传递给部分视图,然后在Client上更新.

问题是文本框没有按预期清除.消息按预期到达视图,因此没有清除TextBoxes没有意义.

然而,它似乎是一个浏览器问题,因为这是生成的HTML,注意,该值没有任何内容:

<input id="Address_Address1" name="Address.Address1" type="text" value="" />

然而,用户看到之前输入的值.

这是控制器:

//Process Order Here


//This should clear out the ViewModel.
order = new OrderViewModel();
order.Message = "Report Added to your cart";

return PartialView("_NewOrderPartial", order);

这是局部视图:

@model NTC.PropertySearch.Models.OrderViewModel

@using (Ajax.BeginForm("NewOrder", "Order", new AjaxOptions { InsertionMode =     InsertionMode.Replace, UpdateTargetId = "neworder" }))
{
<div id="neworder">
    <table>
        <tr>
            <th style="width: 300px;">
                <h3>Enter property address below</h3>
            </th>
            <th style="width: 30px;"></th>
            <th style="width: 300px;">
                <h3>Choose your report below</h3>
            </th>
        </tr>
        <tr>
            <td>
                <div class="form">
                    <table>
                        <tr>
                            <td>
                                @Html.LabelFor(m => m.Address.Address1)
                            </td>

                            <td>
                                @Html.TextBoxFor(m => m.Address.Address1)
                            </td>

                            <td>
                                @Html.ValidationMessageFor(m => m.Address.Address1)
                            </td>
                        </tr>

                        <tr>
                            <td>
                                @Html.LabelFor(m => m.Address.Address2)
                            </td>
                            <td>
                                @Html.TextBoxFor(m => m.Address.Address2)
                            </td>

                            <td>
                                @Html.ValidationMessageFor(m => m.Address.Address2)
                            </td>
                        </tr>

                        <tr>
                            <td>
                                @Html.LabelFor(m => m.Address.City)
                            </td>
                            <td>
                                @Html.TextBoxFor(m => m.Address.City)
                            </td>

                            <td>
                                @Html.ValidationMessageFor(m => m.Address.City)
                            </td>
                        </tr>

                        <tr>
                            <td>
                                @Html.LabelFor(m => m.Address.State)
                            </td>
                            <td>
                                @Html.TextBoxFor(m => m.Address.State)
                            </td>

                            <td>
                                @Html.ValidationMessageFor(m => m.Address.State)
                            </td>
                        </tr>


                        <tr>
                            <td>
                                @Html.LabelFor(m => m.Address.ZipCode)
                            </td>

                            <td>
                                @Html.TextBoxFor(m => m.Address.ZipCode)
                            </td>
                            <td>
                                @Html.ValidationMessageFor(m => m.Address.ZipCode)
                            </td>
                        </tr>

                    </table>

                    <input type="submit" value="Add Report" />
                    @Html.DisplayFor(m=> m.Message)

                </div>
            </td>
                        </tr>
    </table>
</div>        

Answer 1

原因是因为TextBox等Html帮助程序在绑定它们的值时首先查看ModelState,然后才在View模型中查看.当人们尝试在HttpPost控制器操作中修改/清除视图模型的某些值时,通常会发生这种情况.相应的视图将使用初始POSTed值而不是视图模型中的值.

您应该在控制器操作中清除ModelState:

ModelState.Clear();
order = new OrderViewModel();

或者,如果您不想清除整个ModelState(尽管在您重新初始化整个视图模型时似乎就是这种情况),您只能清除一些您想要修改的属性:

ModelState.Remove("SomeProperty");
viewModel.SomeProperty = "some new value";