Question

我正在努力学习mvc，经过多次努力，我终于得到了DropDownListFor的工作。这是工作Dropdownlistfor。

使用ViewModel

public partial class get_preKschedule_Result
    {
        public string start_time { get; set; }
        public Nullable<short> lunch_minutes { get; set; }
        public string dismiss_time { get; set; }
        public Nullable<short> headct { get; set; }
        public byte format { get; set; }
        public Nullable<byte> days_per_week { get; set; }
        public string description { get; set; }
    }

format是学校注册的preK程序的类型。这些值在数据库中存储1-10，因此DropDownListFor将需要所有值和文本。这是视图。

工作视图

@model  DirectoryMVC.Models.get_preKschedule_Result

@{
    List<SelectListItem> listItems = new List<SelectListItem>();
    listItems.Add(new SelectListItem { Text = "Head Start", Value = "6" });
    listItems.Add(new SelectListItem { Text = "Four Year Old At Risk", Value = "7" });
    listItems.Add(new SelectListItem { Text = "Integrated Special Ed", Value = "8" });
    listItems.Add(new SelectListItem { Text = "Reverse Mainstream Special Ed", Value = "9" });
    listItems.Add(new SelectListItem { Text = "All Other District Special Ed", Value = "10" });

}
<div class="col-md-2">
    @Html.DropDownListFor(m => m.format, new SelectList(listItems, "Value", "Text", listItems.Where(x => x.Value == Model.format.ToString())))
    @*listItems*@
</div>

我不知道是否有更简单的方法，但这是我最终让它发挥作用的方式。因此，当我为下一个ViewModel执行完全相同的过程时，它无法正常工作！修改标题的管理员下拉列表未选择任何值或设置任何文本。我还会列出我尝试过的所有内容。我百分之百确定返回的数据是否正确我在监视中验证了模型属性title在将其与SelectListItems值进行比较时的计算结果为真。

非工作ViewModel

public partial class get_administrators_Result
{
    public int admin_id { get; set; }
    public string first_name { get; set; }
    public string last_name { get; set; }
    public string title { get; set; }
    public string email { get; set; }
}

非工作视图

@model  DirectoryMVC.Models.get_administrators_Result

@{ 
    List<SelectListItem> listItems = new List<SelectListItem>();
    listItems.Add(new SelectListItem { Text = "Mr.", Value = "Mr." });
    listItems.Add(new SelectListItem { Text = "Ms.", Value = "Ms." });
    listItems.Add(new SelectListItem { Text = "Dr.", Value = "Dr." });
    listItems.Add(new SelectListItem { Text = "Miss", Value = "Miss" });
    listItems.Add(new SelectListItem { Text = "Mrs.", Value = "Mrs." });
    listItems.Add(new SelectListItem { Text = "Rev.", Value = "Rev." });
}

<div class="col-md-1"> @Html.DropDownListFor(m => m.title, new SelectList(listItems, "Value", "Text", listItems.Where(x=>x.Value == Model.title)))
</div>

我甚至尝试过

@Html.DropDownListFor(m => m.title, new SelectList(listItems, "Value", "Text", Model.title))
@Html.DropDownListFor(m => m.title, new SelectList(listItems, "Value", "Text", (object)Model.title))

以及我能用lambda (m=> m, ...

想到的所有其他组合

修改我也被要求采取行动。此操作返回Index.cshtml。工作视图和非工作视图都是该页面上的EditorTemplates。我不会压缩动作或视图。

ActionMethod

public ActionResult Index(string district)
        {
            getbuilding1_Result bldgResult = de.getbuilding1(district, "1844", null).FirstOrDefault();
            List<get_bldg_contact_email_Result> studentExchangeContact = de.get_bldg_contact_email(district, "1844", 1).ToList();
            get_grades_offered_Result gradesOffered = de.get_grades_offered(district, "1844").FirstOrDefault();
            get_daily_schedule_Result dailyResult = de.get_daily_schedule(district, "1844", 2017).FirstOrDefault();
            List<get_administrators_Result> adminResult = de.get_administrators(district, "1844", 0).ToList();
            List<getabbrev_Result> abbrResult = de.getabbrev().ToList();
            get_total_school_days_Result schoolDays = de.get_total_school_days(district, "1844", 2017).FirstOrDefault();
            List<get_preKschedule_Result> kinderPreKResult = de.get_session_schedule(district, "1844", 2017).ToList();

            if (studentExchangeContact.Count < 1) { studentExchangeContact.Add(new get_bldg_contact_email_Result()); }

            MergeBuilding mergeBuild = new MergeBuilding();
            mergeBuild.schoolDays = schoolDays;
            mergeBuild.gradesOffered = gradesOffered;
            mergeBuild.dailyResult = dailyResult;
            mergeBuild.bldgResult = bldgResult;
            mergeBuild.studentExchangeContact = studentExchangeContact;
            mergeBuild.abbrResult = abbrResult;
            mergeBuild.adminResult = adminResult;
            mergeBuild.kinderPreKResult = kinderPreKResult;

            return View(mergeBuild);
        }

包含视图/父视图？无论这个术语是什么。

@using DirectoryMVC.Models

@model MergeBuilding
@{
    ViewBag.Title = "Building";
    Layout = "~/Views/Shared/_Layout.cshtml";

    List<get_preKschedule_Result> prekSession = Model.kinderPreKResult.Where(x => x.format >= 6).ToList();
    List<get_preKschedule_Result_Result> kinderSession = Model.kinderPreKResult.Where(x => x.format <= 5).ToList();
    List<get_administrators_Result> adminy = Model.adminResult;
}

<h2>Building</h2>
<h4>@Model.bldgResult.bldg_name</h4>

@using (Html.BeginForm("UpdateBuilding", "Building", FormMethod.Post))
{
    <div class="row">
        <div class="col-md-12">
            @Html.EditorFor(m => m.bldgResult, "_FullBuilding")
        </div>
    </div>
    <hr />
    <h4>Student Record Exchange Contact</h4>
    <div class="row">
        <div class="col-md-12">
            @for (var i = 0; i < Model.studentExchangeContact.Count; i++)
            {
                @Html.EditorFor(m => m.studentExchangeContact[i], "_StudentRecordExchange")
            }
        </div>
    </div>
    <hr />
    <div class="row">
        <div class="col-md-12">
            <p class="radio-inline"> Which email address do you want printed in the directory?</p>
            <label class="radio-inline">@Html.RadioButtonFor(m => m.bldgResult.print_email, "b") Building Email</label>
            <label class="radio-inline">@Html.RadioButtonFor(m => m.bldgResult.print_email, "p") Principal/Head Teacher</label>
        </div>
    </div>
    <h4>Administrators</h4>
    <div class="row">
        <div class="col-md-1">
            Title
        </div>
        <div class="col-md-2">
            First name
        </div>
        <div class="col-md-2">
            Last name
        </div>
        <div class="col-md-3">
            Admin code
        </div>
        <div class="col-md-3">
            Email
        </div>
    </div>
    <div class="row">
        <div class="col-md-12">

            @for (var i = 0; i < adminy.Count; i++)
            {
                <div class="row">
                @Html.EditorFor(m => adminy[i],  "_Administrator")
                    </div>
            }
        </div>
    </div>
    <hr />
    <div class="row">
        <div class="col-md-12">
            @Html.EditorFor(m => m.gradesOffered, "_Grades")
        </div>
    </div>
    <div class="row">
        <div class="col-md-12">
            @Html.EditorFor(m => m.bldgResult, "_BuildingProperties")
        </div>
    </div>
    <hr />
    <div class="row">
        <div class="col-md-12">
            @Html.EditorFor(m => m.dailyResult, "_DailySchedule")
        </div>
    </div>
    <br />
    <div class="row">
        <div class="col-md-12">
            @Html.EditorFor(m => m.schoolDays, "_TotalSchoolDays")
        </div>
    </div>
    <hr />
    <h4>Preschool Sessions</h4>
    <div class="row">
        <div class="col-md-12">
            <div class="row">
                <div class="col-md-2">
                    Start
                </div>
                <div class="col-md-2">
                    Lunch Minutes
                </div>
                <div class="col-md-2">
                    Dismiss
                </div>
                <div class="col-md-2">
                    Days Per Week
                </div>
                <div class="col-md-3">
                    PreK Program
                </div>
            </div>
            @for (var i = 0; i < prekSession.Count; i++)
            {
                <div class="row">
                    @Html.EditorFor(m => prekSession[i], "_PreKSession")

                </div>
            }
        </div>
    </div>
}

编辑2

与数值匹配的数据证明。我在非工作视图中将变量名称更改为listItems2，以防出现问题。

编辑3

这似乎是Visual studio / .Net问题。我无法进入title属性。 Intellisense也不会获取模型的title属性。

当我输入@Html.DropDownListFor(m => m.时，我的title没有智能感知。工作DropDownListFor将逐步执行format属性，但它在lambda中也没有intellisense。

当我最初踩过时，我看着this.Model.title具有适当的价值。但lambda表达式并没有进入访问属性！

为什么这一个DropDownListFor工作，而另一个不工作？

0 个答案: