Question

我将viewModel从View1的HttpPost重定向到View2的HttpGet。这没有问题。用户必须接受条款和协议。这应该在viewModel中更改为true（在它为false之前）。然后重定向到view2的HttpPost。

出了点问题。 View2的HttpPost ActionResult接收viewModel，所有参数都为NULL（填充之前）

我该如何解决这个问题？

这是我对View2的HttpGet ActionResult：

public ActionResult Verify(QuestionViewModel viewModel)
{
    //Anrede in Viewbag
    if (viewModelVeri.Per_Salutation == 2)
    {
        ViewBag.Per_Salutation = "Frau";
    }
    else
    {
        ViewBag.Per_Salutation = "Herr";
    }

    int? per_region_id = viewModelVeri.Per_Region;
    int per_region_id_nullable = Convert.ToInt32(per_region_id);

    Region region = _repository.GetRegionById(per_region_id_nullable);

    QuestionViewModel viewModel2 = new QuestionViewModel()
    {
        Reg_Name = region.Reg_Name
    };

    //Regionsname in Viewbag
    ViewBag.Reg_Name = viewModel2.Reg_Name; 

    return View(viewModel);
}

这是我对View2的HttpPost ActionResult：

[HttpPost]
public ActionResult Verify(QuestionViewModel viewModel, string tbButton)
{
    //here the ViewModel-Parameters are already NULL

我的观点：

<div class="panel-body">

@using (Html.BeginForm("Verify", "QuestionForm", FormMethod.Post, new { id = "verifyform" }))
{
@Html.AntiForgeryToken()
    <div class="ctrl-row">
       <div class="form-group">
           <div class="container-fluid">
                 @Html.LabelFor(model => model.Per_Salutation, new { @class = "control-label col-sm-1" })
                 <div class="col-sm-3">
                     @ViewBag.Per_Salutation
                  </div>
            </div>
        </div>
    </div>

    <div class="ctrl-row">
        <div class="form-group">
            <div class="container-fluid">
                @Html.LabelFor(model => model.Per_Name_Last, new { @class = "control-label col-sm-1" })
                <div class="col-sm-3">
                    @Html.DisplayFor(model => model.Per_Name_Last, new { @class = "control-label col-sm-1 non-zero-num" })
                </div>
                @Html.LabelFor(model => model.Per_Name_First, new { @class = "control-label col-sm-1" })
                <div class="col-sm-3">
                    @Html.DisplayFor(model => model.Per_Name_First, new { @class = "control-label col-sm-1 non-zero-num" })
                </div>
            </div>
        </div>
    </div

    <div class="ctrl-row">
        <div class="form-group">
            <div class="container-fluid">
                @Html.LabelFor(model => model.Per_EMail, new { @class = "control-label col-sm-1" })
                <div class="col-sm-8">
                    @Html.DisplayFor(model => model.Per_EMail, new { @class = "control-label col-sm-1 non-zero-num" })
                </div>
            </div>
        </div>
    </div>

    <div class="checkbox">
        <input type="checkbox" id="NutzungsbedingungenAngenommen " />
        <label for="NutzungsbedingungenAngenommen ">
Ich erkläre mich mit den Nutzungsbedingungen einverstanden.
        </label>
    </div>

    <button class="btn btn-default" type="submit" name="tbButton" value="questsend">Senden</button>
}

<script>
    $(document).ready(function () {
        $(".non-zero-num").val($(this).val() == 0 ? ' ' : $(this).val());
    })

    $('#verifyform').on('click', '[value="questsend"]', function () {
        if ($('#agree').is(':checked')) {
            return true;
        }
        else {               
            return false;
        }
    });

</script>

修改

这是我的QuestionViewModel

public class QuestionViewModel
{
    //Other Properties

    [Required(ErrorMessage = "Bitte die Nutzungsbedingungen annehmen!")]
    public bool NutzungsbedingungenAngenommen { get; set; }
}

我的View1的HttpPost控制器：

[HttpPost]
public ActionResult DefaultForm(QuestionViewModel viewModel, string tbButton)
{
    if (ModelState.IsValid)
    {
        try
        {
            if (tbButton.Equals("questsend"))
            {
                return RedirectToAction("Verify", viewModel);
            }
            else if (tbButton.Equals("questupload"))
            {
                //write to DB
                return View(viewModel);
            }
            else
            {
                 dropdownPopulate(viewModel);
                 return View("DefaultForm", viewModel);
            }
        }
        catch
        {
            dropdownPopulate(viewModel);
            return View(viewModel);
        }
    }
    else
    {
        dropdownPopulate(viewModel);
        return View(viewModel);
    }
}

Answer 1

确保声明Razor应使用的模型。
```
@model QuestionViewModel
```
确保HTML输入的名称和ID采用MVC modelbinder预期的格式。我建议使用提供的HtmlHelpers而不是手工编写输入标签。
```
@Html.CheckBoxFor(m => m.Agree)
```
从POST操作中删除string tbButton参数

Answer 2

问题是您使用Html.DisplayFor在View2中显示viewModel的属性值，因此不会将值提交给HttpPost方法，因此viewModel为null当HttpPost for View2被执行时。只会提交<input>，<textarea>和<select>标记中的值。

您可以通过在viewModel内为Html.HiddenFor的所有属性添加Html.BeginForm，将viewModel的值提交给HttpPost for View2。您还应该使用Html.CheckBoxFor(m => m.NutzungsbedingungenAngenommen)作为复选框。像下面的东西应该工作

@using (Html.BeginForm("Verify", "QuestionForm", FormMethod.Post, new { id = "verifyform" }))
{
@Html.AntiForgeryToken()
@Html.HiddenFor(m => m.Per_Salutation)
@Html.HiddenFor(m => m.Per_Name_First)
@Html.HiddenFor(m => m.Per_Name_Last)
.... // Html.HiddenFor for the rest of QuestionViewModel properties

....
.... // the rest of your code inside the form tag
.... // remove <input type="checkbox" id="NutzungsbedingungenAngenommen " />

@Html.CheckBoxFor(m => m.NutzungsbedingungenAngenommen)
<button class="btn btn-default" type="submit" name="tbButton" value="questsend">Senden</button>
}

HttpPost操作方法中的View model参数为null

2 个答案: