Question

我有一个脚手架的“创建”视图，当我试图创建新记录时，返回错误：System.Web.Mvc.WebViewPage<TModel>.Model.get returned null。甚至在我按下“保存”之前。

我的模特：

namespace Itucation.Models
{
    using System;
    using System.Collections.Generic;
    using System.ComponentModel.DataAnnotations;
    using System.ComponentModel.DataAnnotations.Schema;
    using System.Data.Entity.Spatial;

    [Table("jobcoach")]
    public partial class jobcoach
    {

        public int kursist_id { get; set; }

        //[Column(TypeName = "text")]
        public string note { get; set; }

        [Key]
        public int jobcoach_note_id { get; set; }

        [Column("status")]
        //[StringLength(50)]
        [Display(Name = "Status")]
        public string status { get; set; }

        [Column(TypeName = "date")]
        [DisplayFormat(DataFormatString = "{0:yyyy-MM-dd}", ApplyFormatInEditMode = true)]
        [Display(Name = "Success dato")]
        public DateTime? succesDato { get; set; }

        public int? AntalSamtaler { get; set; }

        public virtual kursister kursister { get; set; }

    }
}

我的控制器：

// GET: jobcoach/Create
    public ActionResult Create(int? id)
    {
        ViewBag.kursist_id = new SelectList(db.kursister, "kursist_id", "fornavn");
        ViewBag.status = new SelectList(db.JobcoachStatus, "status", "status");
        ViewBag.ID = id;
        ViewBag.kursist = (from k in db.kursister
                           where k.kursist_id == id
                           select k);
        //var jc = db.jobcoach.Where(u => u.kursist_id == id).ToList().FirstOrDefault();
        var jc = db.jobcoach.Where(r => r.kursist_id == id).ToList().FirstOrDefault();
        if (jc == null)
        {
            // param is not set
        }
        else
        {
            return RedirectToAction("Edit/" + jc.jobcoach_note_id);

        }
        return View();
    }

    // POST: jobcoach/Create
    // To protect from overposting attacks, please enable the specific properties you want to bind to, for 
    // more details see https://go.microsoft.com/fwlink/?LinkId=317598.
    [HttpPost]
    [ValidateAntiForgeryToken]
    public ActionResult Create([Bind(Include = "jobcoach_note_id,kursist_id,note,status,succesDato, AntalSamtaler")] jobcoach jobcoach)
    {
        if (ModelState.IsValid)
        {
            //Brugernavn (current user) skal også indsættes
            jobcoach.note = jobcoach.note + " Af " + User.Identity.Name + " - " + DateTime.Now.ToString();
            db.jobcoach.Add(jobcoach);
            db.SaveChanges();
            return RedirectToAction("Index");
        }

        ViewBag.kursist_id = new SelectList(db.kursister, "kursist_id", "fornavn", jobcoach.kursist_id);
        return View(jobcoach);
    }

我的观点：

@model Itucation.Models.jobcoach

@{
    ViewBag.Title = "Create";
}

<h2>Create</h2>

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

    <div>
        <h4>jobcoach</h4>
        <hr />
        @Html.ValidationSummary(true, "", new { @class = "text-danger" })
        <div>
            @Html.LabelFor(model => model.kursist_id, "Kursist", htmlAttributes: new { @class = "control-label " })
            <div>
                @{
                    foreach (var navn in (ViewBag.kursist))
                    {
                        <text>Kursist ID: </text>@navn.kursist_id <br />
                        <text>Navn:</text> @navn.fornavn<text> </text> @navn.efternavn <br />
                        <text>E-mail: </text>@navn.mail
                    }
                }

                <input type="hidden" name="kursist_id" id="kursist_id" value="@ViewBag.ID" />
                @*@Html.DropDownList("kursist_id", null, htmlAttributes: new { @class = "form-control" })*@
                @Html.ValidationMessageFor(model => model.kursist_id, "", new { @class = "text-danger" })
            </div>
        </div>

        <div>
            @Html.LabelFor(model => model.note, htmlAttributes: new { @class = "control-label " })
            <div>
                @Html.TextAreaFor(model => model.note, new { @class = "form-control", @cols = "100%", @rows = "20", @tabindex = "21" })
                @Html.ValidationMessageFor(model => model.note, "", new { @class = "text-danger" })
            </div>
        </div>

        <div>
            Status
            <div>
                <select id="status">
                    <option value="Uden status">Uden status </option>
                    <option value="Ordinær uddannelse">Ordinær uddannelse</option>
                    <option value="Deltidsjob">Deltidsjob</option>
                    <option value="Praktik">Praktik</option>
                    <option value="Løntilskud privat">Løntilskud privat</option>
                    <option value="Løntilskud offentlig">Løntilskud offentlig</option>
                    <option value="Ordinært job">Ordinært job</option>
                </select>
            </div>
        </div>

        <div>
            Success dato
            <div>
                <input type="date" id="succesDato" name="succesDato" />
            </div>
        </div>

        <div>
            Antal samtaler
            <div>
                <input type="text" id="AntalSamtaler" name="AntalSamtaler" value="@Model.AntalSamtaler"/>
            </div>
        </div>
        @*<div>
                @Html.LabelFor(model => model.status, htmlAttributes: new { @class = "control-label " })
                <div>
                    <select id="status" name="status" class="form-control ">
                        <option>Vælg evt. en status</option>
                        <option value="Ordinært job">Ordinært job</option>
                        <option value="Ordinær uddannelse">Ordinær uddannelse</option>
                        <option value="Deltidsjob">Deltidsjob</option>
                        <option value="Praktik">Praktik</option>
                        <option value="Løntilskud privat">Løntilskud privat</option>
                        <option value="Løntilskud offentlig">Løntilskud offentlig</option>
                    </select>
                </div>
            </div>*@
        <div class="form-group col-md-12">
            <div class="col-md-offset-2 col-md-1">
                <input type="submit" value="Opret" class="btn btn-default" />
            </div>
        </div>
    </div>
}

<div class="col-md-10">
    @Html.ActionLink("Tilbage til listen", "Index")
</div>

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

我希望所有输入字段都有一个“空”视图，在那里我可以输入日期和命中的“保存”。相反，我得到了错误。

错误发生在@Html.ValidationMessageFor(model => model.note, "", new { @class = "text-danger" })行。

我似乎无法弄清楚。我看到许多有关此错误的问题，但似乎没有一个适用于我的问题。

我将非常感谢您的帮助。

Answer 1

这是因为您正在视图和Jobcoach类型的模型之间使用绑定。在视图中，如果要将视图绑定到模型，则必须通过以下方式将其作为参数传递给控制器的View（）方法：

jobcoach jc=new jobcoach();
  return View(jc);

您现在要执行的操作是从“空”模型渲染创建视图，因为您正在使用@Html模型类型的方法助手（LabelFor，ValidationMessageFor ....）

因此，当它试图将视图与模型绑定时，会抛出错误，因为它没有在视图中设置模型属性。

Answer 2

我发现了问题：我试图访问@ Model.AntalSamtaler，但这是空的，因为我还没有保存它。我改变了这一行：

<input type="text" id="AntalSamtaler" name="AntalSamtaler" value="@Model.AntalSamtaler"/>

收件人：

<input type="text" id="AntalSamtaler" name="AntalSamtaler" value="1"/>

我通过在设置了@ Model.AntalSamtaler的“编辑”视图中进行复制/粘贴操作而犯了这个错误。

支架式创建视图返回System.Web.Mvc.WebViewPage <TModel> .Model.get返回null。发布之前

2 个答案: