Question

我无法弄清楚为什么我的视图只将模型的NULL传回给我的控制器。这适用于Edit Post方法。我使用Edit Post方法检查了其他控制器，其结构与此相同，并且它们工作正常。它似乎只是这个视图和控制器。

以下是我的观点：

@model Non_P21_Quote_System_v1._0.Models.gl_code

@{
    ViewBag.Title = "Edit";
    Layout = "~/Views/Shared/_Layout.cshtml";
}

<h2>Edit</h2>

@if (TempData["Message"] != null)
{
    <div style="color:green">
        @TempData["Message"]
    </div><br />
}
@if (ViewBag.error != null)
{
    <div style="color:red">
        <h3>@ViewBag.error</h3>
    </div><br />
}

@using (Html.BeginForm())
{
    @Html.AntiForgeryToken()

    <div class="form-horizontal">
        <h4>gl_code</h4>
        <hr />
        @Html.ValidationSummary(true, "", new { @class = "text-danger" })
        @Html.HiddenFor(model => model.ID)

        <div class="form-group">
            @Html.LabelFor(model => model.GL_code, "GL Code", htmlAttributes: new { @class = "control-label col-md-2" })
            <div class="col-md-10">
                @Html.EditorFor(model => model.GL_code, new { htmlAttributes = new { @class = "form-control" } })
                @Html.ValidationMessageFor(model => model.GL_code, "", new { @class = "text-danger" })
            </div>
        </div>

        <div class="form-group">
            @Html.LabelFor(model => model.GL_description, "Gl Description", htmlAttributes: new { @class = "control-label col-md-2" })
            <div class="col-md-10">
                @Html.EditorFor(model => model.GL_description, new { htmlAttributes = new { @class = "form-control" } })
                @Html.ValidationMessageFor(model => model.GL_description, "", new { @class = "text-danger" })
            </div>
        </div>

        <div class="form-group">
            @Html.LabelFor(model => model.expense_type_ID, "Expense", htmlAttributes: new { @class = "control-label col-md-2" })
            <div class="col-md-10">
                @Html.DropDownList("expense_type_ID", null, htmlAttributes: new { @class = "form-control" })
                @Html.ValidationMessageFor(model => model.expense_type_ID, "", new { @class = "text-danger" })
            </div>
        </div>

        <div class="form-group">
            @Html.LabelFor(model => model.eag, "Employee Account Group", htmlAttributes: new { @class = "control-label col-md-2" })
            <div class="col-md-10">
                @Html.DropDownList("eag", null, htmlAttributes: new { @class = "form-control" })
                @Html.ValidationMessageFor(model => model.eag, "", new { @class = "text-danger" })
            </div>
        </div>

        <div class="form-group">
            <div class="col-md-offset-2 col-md-10">
                <input type="submit" value="Save" class="btn btn-default" />
            </div>
        </div>
    </div>
}

<div>
    @Html.ActionLink("Back to List", "gl_Index")
</div>

@section Scripts {
    @Scripts.Render("~/bundles/jqueryval")
}

这是我的控制器方法：

[HttpPost]
[ValidateAntiForgeryToken]
public async Task<ActionResult> Edit([Bind(Include = "ID,GL_code,GL_description,expense_type_ID,eag")] gl_code gl_code)
{
    if (ModelState.IsValid)
    {           
        db.Entry(gl_code).State = EntityState.Modified;
        await db.SaveChangesAsync();
        return RedirectToAction("gl_Index");      
    }
    ViewBag.eag = new SelectList(db.employee_account_group, "ID", "eag_name");
    ViewBag.expense_type_ID = new SelectList(db.expense_type, "ID", "type", gl_code.expense_type_ID);
    return View(gl_code);
}

当我调试它时，我看到传入的模型的值为NULL。我在控制器端看到这个在Edit方法的参数部分。

Answer 1

它为null，因为您的模型包含名为gl_code的属性，并且您还在POST方法中为模型gl_code命名了参数。

更改其中一个名称，模型将正确绑定。

内部发生的事情是表单为您的案例gl_code=someValue提交了每个成功表单控件的名称/值对。 DefaultModelBinder首先初始化模型的新实例。然后，它会读取表单值并找到模型中属性的匹配项，并将其设置为someValue。但它也在方法参数中找到匹配项并尝试将参数值设置为someValue，但失败（因为您无法执行gl_code gl_code = "someValue";）并且模型变为null。

Answer 2

看来你的视图模型中有一个名为gl_code的属性。在控制器中，您还将视图模型称为gl_code。

尝试更改此内容。

public async Task<ActionResult> Edit(gl_code gl_code)

要

public async Task<ActionResult> Edit(gl_code model)

Asp.Net MVC：为什么我的视图将NULL模型传递回我的控制器？

2 个答案: