如何将字符串列表转换为IEnumerable类型？

Question

I am doing a registration System for two different users; 我正在为两个不同的用户创建注册系统； Staff and Student. 教职员工和学生。 and now in the fields I also have a Dropdown List. 现在在字段中，我还有一个下拉列表。 the other Fields which are Text fields are working perfectly and data can be saved to the Database, but My dropDown is giving me an error that says The ViewData item that has the key Faculty is of type System.String but must be of type IEnumerable<SelectListItem> . 其他“文本”字段则可以正常工作，并且可以将数据保存到数据库，但是我的dropDown给我一个错误，提示具有Faculty键的ViewData项的类型为System.String但必须为IEnumerable<SelectListItem> 。

Model 模型

public class RegisterClient
{

    public int UserID { get; set; }

    [Required(ErrorMessage ="Please Enter Department Name")]
    [Display(Name="Department")]
    [RegularExpression(@"^[a-zA-Z]+[ a-zA-Z-_]*$", ErrorMessage = "Use    Characters only")]
    [StringLength(100)]
    public string Department { get; set; }


    public string Faculty { get; set; }


    [Required(ErrorMessage ="Please enter Name")]
    [RegularExpression(@"^[a-zA-Z]+[ a-zA-Z-_]*$", ErrorMessage = "Use     Characters only")]
    [StringLength(50)]
    public string Name { get; set; }

    [Required(ErrorMessage ="Please enter Contact number")]
    [Display(Name="Contact Number")]
    [RegularExpression(@"^\(?([0-9]{3})\)?[-. ]?([0-9]{3})[-. ]?([0-9]  {4})$", ErrorMessage = "Entered phone format is not valid.")]
    [StringLength(10, ErrorMessage ="Contact Number must be 10 numbers")]
    public string Contact_Nr { get; set; }

    [Required(ErrorMessage ="Please Enter Surname")]
    [RegularExpression(@"^[a-zA-Z]+[ a-zA-Z-_]*$", ErrorMessage = "Use   Characters only")]
    [StringLength(50)]
    public string Surname { get; set; }

    [Required(ErrorMessage = "Please Enter Staff Number")]
    [StringLength(5, MinimumLength = 5, ErrorMessage ="Staff Number must be   5 digits only")]
    [Display(Name="Staff Number")]
    [RegularExpression("([1-9][0-9]*)", ErrorMessage = "Staff Number must be   numbers only")]
    public string Access_Num{ get; set; }

    [Required(ErrorMessage ="Please enter Email Address")]
    [EmailAddress]
    [Display(Name="Email")]
    [RegularExpression(".+\\@.+\\..+", ErrorMessage = "Please Enter your   valid email which contains the @ Sign")]
    [StringLength(128)]
    public string EmailID { get; set; }


  }

View 视图

@model EbikesRegistrationSystem.Models.RegisterClient

  @{
  ViewBag.Title = "Register";
  }

  <h2>Register</h2>
  <body style="background:#FFD24A">

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

    <div class="form-horizontal">
        <h4>Staff Registration</h4>
        <hr />
        @Html.ValidationSummary(true, "", new { @class = "text-danger" })


        @{
            ViewBag.Title = "uYilo";
        }

        <h2></h2>
        @if (ViewData["Message"] != null)
        {
            <script language="javascript">
    alert('@ViewData["Message"]');
            </script>
        }

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

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


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



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

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



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


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







        <div class="form-group">
            <div class="col-md-offset-2 col-md-10">
                <input type="submit" value="Register" class="btn btn-  default" onclick="clearField()" />
            </div>
        </div>
    </div>
}

<div>
    @*@Html.ActionLink("Back to List", "Index")*@
</div>
<script>
    var clearField = function () {

        $(".form-control")
    }
</script>
@section Scripts {
    @Scripts.Render("~/bundles/jqueryval")
}
</body>

Controller 调节器

public class UserController : Controller
{
    private DataClasses1DataContext db = new DataClasses1DataContext();
    // GET: User
    public ActionResult Register()
    {

        DataClasses1DataContext db = new DataClasses1DataContext();
        ViewBag.Faculties = new SelectList(db.Faculties, "Id", "Name");
        return View();
    }



    [HttpPost]
    [ValidateAntiForgeryToken]
    public ActionResult Register(RegisterClient U)
    {
        if (ModelState.IsValid)
        {
            try
            {
                using (DataClasses1DataContext db = new   DataClasses1DataContext())
                {

                    {


                        User newone = new User();

                        newone.EmailID = U.EmailID;
                        newone.Name = U.Name;
                        newone.Surname = U.Surname;
                        newone.Contact_Nr = U.Contact_Nr;
                        newone.Department = U.Department;
                        newone.Access_Num = U.Access_Num;


                        var count = db.Users.Count(a => a.EmailID ==    U.EmailID);
                        if (count == 0)
                        {
                            db.Users.InsertOnSubmit(newone);
                            db.SubmitChanges();
                            ViewData["Message"] = "Successful Registration";
                            ModelState.Clear();

                        }
                        else
                        {
                            // something to do if user exist...
                            ViewData["Message"] = "User Exists, Register   with a new Email Address";
                            ModelState.Clear();
                        }


                    }

                }
            }
            catch (Exception ex)
            {
                string error = ex.Message;
            }

        }

        return View(U);
    }

Answer 1

Change to ViewBag.Faculties 更改为ViewBag.Faculties

You should use DropDownListFor extension for clarity. 为了清楚起见，您应该使用DropDownListFor扩展。

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

如何将字符串列表转换为IEnumerable类型？

问题描述

1 个解决方案

解决方案1
1 已采纳 2015-12-02 07:05:00

如何将字符串列表转换为IEnumerable类型？

问题描述

1 个解决方案

解决方案1 1 已采纳 2015-12-02 07:05:00

解决方案1
1 已采纳 2015-12-02 07:05:00