c# - ViewModel 属性在 HttpPost 上保持为空

Question

我完全不明白为什么这个简单的概念似乎不起作用。我有一个 ViewModel、一个 Controller 和一个 View ...

这是我的基本 ViewModel

public class CreateProfessionalEducationViewModel
{

    public Models.ProfessionalEducation ProfessionalEducation;

    public int ConsultantId;

    public CreateProfessionalEducationViewModel() {} // parameterless constr

}

这是我的两个 Controller 方法

 public ActionResult Create(int id)
    {
        var viewModel = new CreateProfessionalEducationViewModel
        {
            ConsultantId = id
        };

        return View(viewModel);
    }

    //
    // POST: /ProfessionalEducation/Create

    [HttpPost]
    [ValidateAntiForgeryToken]
    public ActionResult Create(CreateProfessionalEducationViewModel collection)
    {
        if (ModelState.IsValid)
        {
            //db.ProfessionalEducations.Add(professionaleducation);
            db.SaveChanges();
            return RedirectToAction("Index");
        }

        return View();
    }

还有我的看法...

@model Axxes_Virtual_Resume_MVC.ViewModel.ProfessionalEducation.CreateProfessionalEducationViewModel
@using (Html.BeginForm("Create", "ProfessionalEducation")) {
@Html.AntiForgeryToken()
@Html.ValidationSummary(true)

<fieldset>
    <legend>ProfessionalEducation</legend>

    <div class="editor-label">
        @Html.LabelFor(model => model.ProfessionalEducation.Year)
    </div>
    <div class="editor-field">
        @Html.EditorFor(model => model.ProfessionalEducation.Year)
        @Html.ValidationMessageFor(model => model.ProfessionalEducation.Year)
    </div>

    <div class="editor-label">
        @Html.LabelFor(model => model.ProfessionalEducation.Title)
    </div>
    <div class="editor-field">
        @Html.EditorFor(model => model.ProfessionalEducation.Title)
        @Html.ValidationMessageFor(model => model.ProfessionalEducation.Title)
    </div>
    @Html.HiddenFor(model => model.ConsultantId)
    <p>
        <input type="submit" value="Create" />
    </p>
</fieldset>
}

由于某些奇怪的原因，当回发到我的 Controller 中的 HttpPost Create 方法时，我的 ConsultantId 为 0 并且 ProfessionalEducation 在我的 ViewModel 中为 null。

这应该是最基本的，我忘了什么？

提前致谢!

Answer 1

主要问题是，DefaultModelBinder(从 HttpFormCollection 重建 View 模型)这个疯子作用于属性而不是变量。

如果我没记错的话，我相信如果您在 Viewmodel 中使用类似内部对象并直接在 View 中访问它们的属性，则默认模型绑定(bind)器不会工作得很好。

尝试这样的事情:

public class CreateProfessionalEducationViewModel
{
    public int ConsultantId  { get; set; }

    public int ProfessionalEducationYear { get; set; }

    public string ProfessionalEducationTitle  { get; set; }
}

当然还有风景

@model Axxes_Virtual_Resume_MVC.ViewModel.ProfessionalEducation.CreateProfessionalEducationViewModel
@using (Html.BeginForm("Create", "ProfessionalEducation")) {
@Html.AntiForgeryToken()
@Html.ValidationSummary(true)

<fieldset>
    <legend>ProfessionalEducation</legend>

    <div class="editor-label">
        @Html.LabelFor(model => model.ProfessionalEducationYear )
    </div>
    <div class="editor-field">
        @Html.EditorFor(model => model.ProfessionalEducationYear )
        @Html.ValidationMessageFor(model => model.ProfessionalEducationYear )
    </div>

    <div class="editor-label">
        @Html.LabelFor(model => model.ProfessionalEducationTitle)
    </div>
    <div class="editor-field">
        @Html.EditorFor(model => model.ProfessionalEducationTitle)
        @Html.ValidationMessageFor(model => model.ProfessionalEducationTitle)
    </div>
    @Html.HiddenFor(model => model.ConsultantId)
    <p>
        <input type="submit" value="Create" />
    </p>
</fieldset>
}

通常尽量避免在 ViewModel 中引用 Model 对象(但这只是设计规则)