asp.net-mvc - MVC 中的默认值在 http 发布之前创建 View

Question

您好，我正在尝试在创建 View 中使用“DateTime.Now”默认日期。并将“事件”字段设置为“真”

以下代码在 Controller 的以下操作中执行此操作:

// POST: RequestTypes/Create
// To protect from overposting attacks, please enable the specific properties you want to bind to, for
// more details see http://go.microsoft.com/fwlink/?LinkId=317598.
[HttpPost]
[ValidateAntiForgeryToken]
public async Task<ActionResult> Create([Bind(Include = "Id,RequestTypeDescription,LastUpdated,Active,Team")] RequestType requestType)
{
    if (ModelState.IsValid)
    {
        db.RequestTypes.Add(requestType);
        requestType.LastUpdated = System.DateTime.Now;
        requestType.Active = true;
        await db.SaveChangesAsync();
        return RedirectToAction("Index");
    }

    ViewBag.Team = new SelectList(db.Teams, "Id", "TeamDescription", requestType.Team);
    return View(requestType);
}

这是保存时默认的 httppost 代码。

我想做的是默认这些字段，以便它们在创建 View 首次启动时显示 - 在以下操作中使用以下代码:

// GET: RequestTypes/Create
public ActionResult Create()
{
    ViewBag.Team = new SelectList(db.Teams, "Id", "TeamDescription");
    ViewBag.LastUpdated = System.DateTime.Now;
    return View();
}

我的Create View代码是MVC脚手架创建的标准:

@model ManageHR5.Models.RequestType

@{
    ViewBag.Title = "Create";
}

<h2>Create</h2>

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

    <div class="form-horizontal">
        <h4>RequestType</h4>
        <hr />
        @Html.ValidationSummary(true, "", new { @class = "text-danger" })
        <div class="form-group">
            @Html.LabelFor(model => model.RequestTypeDescription, htmlAttributes: new { @class = "control-label col-md-2" })
            <div class="col-md-10">
                @Html.EditorFor(model => model.RequestTypeDescription, new { htmlAttributes = new { @class = "form-control" } })
                @Html.ValidationMessageFor(model => model.RequestTypeDescription, "", new { @class = "text-danger" })
            </div>
        </div>

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

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

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

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

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

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

当我运行应用程序并启动创建页面时，启动创建页面时不会显示默认值。

我不明白什么？

(MVC 的新手 :( )

Answer 1

您在 Get 上的模型中设置它们以用于显示目的

// GET: RequestTypes/Create
public ActionResult Create() {        
    ViewBag.Team = new SelectList(db.Teams, "Id", "TeamDescription");
    var model = new RequestType();
    model.LastUpdated = System.DateTime.Now;
    model.Active = true;
    return View(model);
}

但是就像提供的评论中指出的那样

You set them immediately before you save the object in the POST method