如何将字符串List转换为类型IEnumerable
本文关键字：类型 IEnumerable 转换 List 字符串 | 更新日期: 2023-09-27 18:25:21
我正在为两个不同的用户进行注册系统；员工和学生。现在在字段中，我还有一个下拉列表。其他作为文本字段的字段工作正常，数据可以保存到数据库中，但我的下拉菜单显示一个错误，即具有关键字Faculty的ViewData项的类型为System.String，但必须为IEnumerable<SelectListItem>。
型号
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; }
}
查看
@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>
控制器
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);
}
- 更改为
ViewBag.Faculties -
为了清晰起见，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>