c# - 提交表单后，值消失了

Question

提交表单后，“仅显示”值消失了， 有谁知道错误是什么？

在 View 中，我使用@Html.textboxfor 并将 ViewBag.StaffId 值用作“只读”变量，如果我提交有错误的表单，ViewBag.StaffId 值将消失

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

        <div class="form-group">
            @Html.LabelFor(model => model.StaffInfo.Cname, htmlAttributes: new { @class = "control-label col-md-2" })
            <div class="col-md-10">
                @Html.TextBoxFor(model => model.StaffInfo.Cname, new { @Value = ViewBag.CName, @readonly = "readonly", @class = "form-control" })
                @Html.ValidationMessageFor(model => model.StaffInfo.Cname, "", new { @class = "text-danger" })
            </div>
        </div>

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

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

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

Controller 代码:

[HttpPost]
[ValidateAntiForgeryToken]
public ActionResult Create([Bind(Include = "StaffId, Tdate, Edate")] TrainingRecord trainingRecord)
{
    if (ModelState.IsValid)
    {
        db.TrainingRecordDBSet.Add(trainingRecord);
        db.SaveChanges();
        return RedirectToAction("Search", "TrainingRecords", new { id = trainingRecord.StaffId });
    } 
    return View(trainingRecord);
}

Answer 1

你在帖子后最绑定(bind)模型 例如

public ActionResult myController(){
  var model= new myModel();
  return View(model);
}

[HttpPost]
public ActionResult myController(myModel model){
  model.StaffId = 1;
  return View(model);
}