在 ASP.NET MVC 中填充 DropDownList

阿尔珀

以下代码是创建用户。我有一个用户类,我需要在这里创建用户。但是我有一个人的部门 ID,该部门 ID 指的是数据库中名为部门的另一个表。

public ActionResult Create()
{
    // disable lazy because of error it creates
    _db.Configuration.LazyLoadingEnabled = false;
    var data = _db.Departments.OrderBy(a => a.DepartmentId).ToList();
    ViewData["DepartmentList"] = data;

    return View();
}

这是视图:

@{
    var departmentLists = ViewData["DepartmentList"]; // Cast the list
}

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

这个model.department 部分是我丢失的地方。我需要按照列表的顺序列出我的部门,当用户选择时,我想选择部门的 id。像这样;

在此处输入图片说明

所以我想让用户看到

部门名称+子部门名称

当他们从列表中选择时,选择的东西是

部门编号

所以我可以像这样添加到数据库中。

这是我的 Create Post 方法:

public ActionResult Create([Bind(Include = "ID,LastName,FirstMidName,EnrollmentDate,Email,Department,Position,Active")] User user)
{
    if (ModelState.IsValid)
    {
        _db.Users.Add(user);
        _db.SaveChanges();
        return RedirectToAction("Index");
    }

     return View(user);
 }

她是我的 User 类;

public class User
{
    [DatabaseGenerated(DatabaseGeneratedOption.Identity)]
    public int Id { get; set; }

    public int DepartmentId { get; set; }

    // Other fields removed for brevity
}

这是Department课堂;

public class Department
{
    [DatabaseGenerated(DatabaseGeneratedOption.Identity)]
    public int DepartmentId { get; set; }

    public string DepartmentName { get; set; }

    public string SubDepartmentName { get; set; }
}
坦维尔·阿杰尔

编写您的CreateGET 方法如下:

public ActionResult Create()
{
    // disable lazy because of error it creates
    _db.Configuration.LazyLoadingEnabled = false;

    var departmentList = _db.Departments.Select(d => new
     {
        d.DepartmentId,
        DepartmentName = d.DepartmentName + " " + d.SubDepartmentName
     }).OrderBy(a => a.DepartmentId).ToList();

    ViewBag.DepartmentList = new SelectList(departmentList,"DepartmentId","DepartmentName");

    return View();
}

然后在视图中:

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

另一个问题是你的Create POST方法。您不允许您DepartmentId传入Bind包含列表。Create POST按如下方式更新您的方法:

public ActionResult Create([Bind(Include = "ID,LastName,FirstMidName,EnrollmentDate,Email,DepartmentId,Position,Active")] User user)
{
    if (ModelState.IsValid)
    {
       _db.Users.Add(user);
       _db.SaveChanges();
       return RedirectToAction("Index");
    }

    return View(user);
} 

本文收集自互联网,转载请注明来源。

如有侵权,请联系 [email protected] 删除。

编辑于
0

我来说两句

0 条评论
登录 后参与评论

相关文章