Question

我有一个复杂类型作为属性的模型。我为复杂的子类型创建了一个自定义的DisplayEditor，并在加载页面时正确绑定。在编辑完成后发布页面时，Dependents类型将设置为null。以下是代表子Dependents属性的Employee模型的代码：

[Display(Name = "Dependents")]
[DataType(DataType.MultilineText)]
public List<Dependent> Dependents { get; set; }

以下是Dependent模型：

[Serializable]
public class Dependent : Person
{
    public Dependent()
    {
        Deduction deduction = new Deduction(this) { Amount = Constants.DependentDeductionAmount };
        this.Deduction = deduction;
    }

    [Key]
    [HiddenInput(DisplayValue = false)]
    public int DependentId { get; set; }

    [Required]
    [Display(Name = "Dependent Type")]
    public DependentType DependentType { get; set; }

    [Required]
    public override double DeductionAmount => Constants.DependentDeductionAmount;
}

员工控制器上的2个编辑操作方法（我尝试过TryUpdateModel，不起作用）：

    public ViewResult Edit(int employeeId)
    {
        if (employeeId < 0) throw new ArgumentOutOfRangeException(nameof(employeeId));

        Employee employee = _employeeRepository.Employees.FirstOrDefault(e => e.EmployeeId == employeeId);

        bool result = TryUpdateModel(employee, new FormValueProvider(ControllerContext));

        return View(employee);
    }

    [HttpPost]
    public ActionResult Edit(Employee employee)
    {
        if (employee == null) throw new ArgumentNullException(nameof(employee));

        if (ModelState.IsValid)
        {
            employee.Changed = true;
            employee.Dependents.ForEach(d => d.Changed = true);
            _employeeRepository.SaveEmployee(employee);
            TempData["message"] = $"{employee} has been saved.";
            return RedirectToAction("Index");
        }
        else {
            // there is something wrong with the data values
            return View(employee);
        }
    }

这是Edit.cshtml：

@model Paylocity.HR.Domain.Entities.Employee

@{
    ViewBag.Title = $"{"Edit"} {Model}";
}

<div class="panel panel-default">
    <div class="panel-heading">
        <h3>@ViewBag.Title</h3>
</div>
@using (Html.BeginForm("Edit", "Employee"))
{
    @Html.AntiForgeryToken()

    <div class="form-horizontal">
        <hr/>
        @Html.ValidationSummary(true, "", new {@class = "text-danger"})
        <h4>Employee</h4>
        <div class="form-group">
            @Html.LabelFor(model => model.FirstName, htmlAttributes: new {@class = "control-label col-md-2"})
            <div class="col-md-10">
                @Html.EditorFor(model => model.FirstName, new {htmlAttributes = new {@class = "form-control"}})
                @Html.ValidationMessageFor(model => model.FirstName, "", new {@class = "text-danger"})
            </div>
        </div>
        <div class="form-group">
            @Html.LabelFor(model => model.LastName, htmlAttributes: new {@class = "control-label col-md-2"})
            <div class="col-md-10">
                @Html.EditorFor(model => model.LastName, new {htmlAttributes = new {@class = "form-control"}})
                @Html.ValidationMessageFor(model => model.LastName, "", new {@class = "text-danger"})
            </div>
        </div>
        <hr/>
        @Html.EditorFor(model => model.Dependents, "Dependents")   
        @Html.HiddenFor(model => model.EmployeeId)
    </div>
    <div class="panel-footer">
        <input type="submit" value="Save" class="btn btn-primary"/>
        @Html.ActionLink("Cancel and return to List", "Index", null, new {@class = "btn btn-default"})
    </div>
}
</div>

这是Dependent.cshtml EditorTemplate：

@model IEnumerable<Dependent>
@using Paylocity.HR.Domain.Entities

@foreach (var dep in Model)
{
<h4>Dependent</h4>
<div class="form-group">
    @Html.LabelFor(m => dep.FirstName, htmlAttributes: new { @class = "control-label col-md-2" })
    <div class="col-md-10">
        @Html.EditorFor(m => dep.FirstName, new { htmlAttributes = new { @class = "form-control" } })
        @Html.ValidationMessageFor(m => dep.FirstName, "", new { @class = "text-danger" })
    </div>
</div>
<div class="form-group">
    @Html.LabelFor(m => dep.LastName, htmlAttributes: new { @class = "control-label col-md-2" })
    <div class="col-md-10">
        @Html.EditorFor(m => dep.LastName, new { htmlAttributes = new { @class = "form-control" } })
        @Html.ValidationMessageFor(model => dep.LastName, "", new { @class = "text-danger" })
    </div>
</div>
<div class="form-group">
    @Html.LabelFor(m => dep.DependentType, htmlAttributes: new { @class = "control-label col-md-2" })
    <div class="col-md-10">
        @Html.EnumDropDownListFor(m => dep.DependentType, new { @class = "form-control" })
        @Html.ValidationMessageFor(m => dep.DependentType, "", new { @class = "text-danger" })
    </div>
</div>
<hr />
}

employee对象绑定正确且可更新，它只是没有正确绑定的dependents子类型。 HTML正在显示Dependent表单字段的正确ID /名称（我相信？）。我是否需要实现某种自定义绑定器代码，或者我错过了一些明显的东西？

这是我关于SO的第一个问题，我希望我提供了足够的信息。

Answer 1

我认为您的问题是生成项目列表的方式。

使用index而不是foreach。

因此你的Dependent.cshtml EditorTemplate

做类似的事情：

@for(int i = 0; i < Model.Count(); i++)
{
<h4>Dependent</h4>
<div class="form-group">
    @Html.LabelFor(m => Model[i].FirstName, htmlAttributes: new { @class = "control-label col-md-2" })
    <div class="col-md-10">
        @Html.EditorFor(m => Model[i].FirstName, new { htmlAttributes = new { @class = "form-control" } })
        @Html.ValidationMessageFor(m => Model[i].FirstName, "", new { @class = "text-danger" })
    </div>
</div>

// rest field follow same pattern
}

有关绑定列表的更多信息，请查看此帖子 http://haacked.com/archive/2008/10/23/model-binding-to-a-list.aspx/

Answer 2

将Dependent.cshtml模板中的模型更改为@model Dependent（不能IEnumerable<T>）并删除生成foreach属性的name循环与您的模型无关（以及无效的html的重复id属性）

它还需要位于/Views/Shared/EditorTemplates/或/Views/yourControllerName/EditorTemplates/文件夹

中

@model Dependent
...
@Html.EditorFor(m => m.FirstName, new { htmlAttributes = new { @class = "form-control" } })
...
@Html.EditorFor(m => m.LastName, new { htmlAttributes = new { @class = "form-control" } })

等。然后在主视图中，使用

@Html.EditorFor(model => model.Dependents)

EditorFor()方法接受IEnumerable<T>，并为集合中的每个项目生成正确的html，包括带有索引器的正确name属性

自定义EditorTemplate未正确返回表单值

2 个答案: