Question

我有一个页面，其中包含多个表单来编辑单个测验的问题，每个问题都有自己的答案列表。因此，对于此测验中的每个问题，都有一个表单供用户编辑问题（和答案），见下文：

@model OLTINT.Areas.admin.ViewModels.OldQuizQAViewModel
<h1>Edit @Model.QuizTitle quiz</h1>
<hr />
<p class="breadcrumb">
    @Html.ActionLink(HttpUtility.HtmlDecode("&#9668;") + " Back to List", "Quizzes", new { id = Model.CourseID }, new { @class = "" })
</p>
@for (int j = 0; j < Model.OldQuizQuestions.Count(); j++)
{
    using (Ajax.BeginForm("EditQuiz", "Course", null, new AjaxOptions
    {
        HttpMethod = "POST",
        InsertionMode = InsertionMode.Replace,
        UpdateTargetId = "button"
    }))
    {
        @Html.AntiForgeryToken()
        @Html.HiddenFor(model => model.QuizID)
        @Html.HiddenFor(model => model.OldQuizQuestions[j].QuizQuestionID)

        <p class="form_title">Question number @Model.OldQuizQuestions[j].Order</p>
        <div class="resize_input">@Html.EditorFor(model => model.OldQuizQuestions[j].Question)</div>
        <p class="form_title">@Html.LabelFor(model => model.OldQuizQuestions[j].Type)</p>
        <div class="resize_input">@Html.DropDownListFor(model => model.OldQuizQuestions[j].Type, ViewBag.types, "Please choose...", new { @class = "chosen-select" })</div>

        <p class="form_title">Choose correct answers</p>
        Char x = 'a';
        for (int i = 0; i < Model.OldQuizQuestions[j].OldQuizAnswers.Count(); i++)
        {
            x++;
            if (i == 0)
            {
                x = 'a';
            }
            <div style="display:table; width:100%;">
                <div class="divTableCell" style="padding:0 10px 10px 0; vertical-align:middle; min-width:6%;">
                    @Html.CheckBoxFor(model => model.OldQuizQuestions[j].OldQuizAnswers[i].Correct, new { style = "" })
                    @Html.LabelFor(model => model.OldQuizQuestions[j].OldQuizAnswers[i].Correct, "["+ x +"]")
                </div>
                <div class="divTableCell quiz_input">
                    @Html.HiddenFor(model => model.OldQuizQuestions[j].OldQuizAnswers[i].QuizAnsID)
                    @Html.EditorFor(model => model.OldQuizQuestions[j].OldQuizAnswers[i].Answer)
                </div>
            </div>
        }
        <div class="button_container">
            <p id="button"></p>
            @Html.ActionLink("Delete this question", "DeleteQuestion", new { id = Model.OldQuizQuestions[j].QuizQuestionID }, new { @class = "button button_red button_not_full_width" })
            <input type="submit" value="Save" class="button button_orange button_not_full_width" />
        </div>
        <hr />
    }
}

OldQuizQAViewModel：

public class OldQuizQAViewModel
{
    public int CourseID { get; set; }
    public int? QuizID { get; set; }
    public string QuizTitle { get; set; }
    public IList<OldQuizQuestions> OldQuizQuestions { get; set; }
}

OldQuizQuestions：

public class OldQuizQuestions
{
    [Key]
    public int QuizQuestionID { get; set; }
    public int OldQuizID { get; set; }
    [Required]
    public string Question { get; set; }
    [Required]
    public int Order { get; set; }
    [Required]
    public int Type { get; set; }

    public virtual IList<OldQuizAnswers> OldQuizAnswers { get; set; }
    public virtual OldQuiz OldQuiz { get; set; }

}

OldQuizAnswers：

public class OldQuizAnswers
{
    [Key]
    public int QuizAnsID { get; set; }
    public int QuizQuestionID { get; set; }
    public string Answer { get; set; }
    public int Order { get; set; }
    public bool Correct { get; set; }
    public bool Chosen { get; set; }

    public virtual OldQuizQuestions OldQuizQuestions { get; set; }
}

控制器：

    [HttpPost]
    [ValidateAntiForgeryToken]
    public ActionResult EditQuiz(OldQuizQAViewModel model)
    {
        var questiondata = model.OldQuizQuestions.Single();

        if (ModelState.IsValid)
        {
            OldQuizQuestions updatequestion = db.OldQuizQuestions
                .SingleOrDefault(x => x.QuizQuestionID == questiondata.QuizQuestionID);

            updatequestion.Question = questiondata.Question;
            updatequestion.Type = questiondata.Type;

            db.Entry(updatequestion).State = EntityState.Modified;
            db.SaveChanges();

            foreach (var answer in questiondata.OldQuizAnswers)
            {
                var updateanswer = updatequestion.OldQuizAnswers
                    .First(x => x.QuizAnsID == answer.QuizAnsID);

                updateanswer.Answer = answer.Answer;
                updateanswer.Correct = answer.Correct;

                db.Entry(updateanswer).State = EntityState.Modified;
                db.SaveChanges();
            }

            return Content("<span style='font-weight:300; font-size:1.2em; color: green; '>Saved!</span>");
        }
        return Content("<span class='errortext'>Please correct the marked fields!</span>");
    }

现在这可以正常工作，如果我想编辑第一个问题，但是当我编辑其他任何东西时我的控制器只是说null但是当我检查被发布的数据时，一切都在那里（例如当我尝试编辑时问题2）：

我已经在这里看了很多关于模型绑定到列表的查询，但没有人帮助过。任何人都可以看到我在哪里出错吗？

MVC模型绑定到列表 - 仅适用于列表中的第一个项目

0 个答案: