没有类型为'IEnumerable< SelectListItem>'的ViewData项有关键'ddldepartmentlist' [英] There is no ViewData item of type 'IEnumerable<SelectListItem>' that has the key 'ddldepartmentlist'

问题描述

我是ASP.NET MVC的新手我想使用HTML Helper在mvc 4中使用下拉列表。我被困在这里。我已经给出了以下代码。



员工控制员

 [HttpGet] 
 public ActionResult _GetEmployeeSpeciality （字符串id）
 {
 
 DataTable dtdepartment = new DataTable（）; 
 FPDiabeticService.BoDataTable BODT = new FPDiabeticService.BoDataTable（）; 
 BODT = new Models.Frontdesk（）。FetchAllDepartmentList（）; 
 dtdepartment = BODT.PassTable; 
 List< SelectListItem> ddldepartmentlist = new List< SelectListItem>（）; 
 ddldepartmentlist.Add（new SelectListItem {Text =--- Select a Department ---，Value = -  1，Selected = true}）; 
 if（dtdepartment.Rows.Count> 0）
 {
 for（int i = 0; i< dtdepartment.Rows.Count; i ++）
 {
 ddldepartmentlist.Add（new SelectListItem {text = dtdepartment.Rows [i] [department]。ToString（），Value = dtdepartment.Rows [i] [departmentID]。ToString（）}）; 
} 
} 
 ViewData [ddldepartmentlist] = ddldepartmentlist; 
返回视图（_ GetEmployeeSpeciality）; 
} 
 

查看

 @ Html.DropDownList（ddldepartmentlist）
 

或

 @ Html.DropDownList（ddldepartmentlist，ViewData [ddldepartmentlist]）

当我运行此

没有类型为'IEnumerable< SelectListItem>'的ViewData项目具有键'ddldepartmentlist'

错误发生可以有人帮忙。





谢谢

parithi

解决方案

您尚未将视图状态转换为IEnumerable< SelectListItem>这就是为什么它给出错误尝试它将起作用

 @ Html.DropDownList（ddldepartmentlist，ViewData [ddldepartmentlist]为IEnumerable< SelectListItem>）

Hi,

I am new to ASP.NET MVC I want to use a dropdownlist in mvc 4 using HTML Helper. I am stuck here. i have given the code below.

Employee controller

[HttpGet]
      public ActionResult _GetEmployeeSpeciality(string id)
      {

          DataTable dtdepartment = new DataTable();
          FPDiabeticService.BoDataTable BODT = new FPDiabeticService.BoDataTable();
          BODT = new Models.Frontdesk().FetchAllDepartmentList();
          dtdepartment = BODT.PassTable;
          List<SelectListItem> ddldepartmentlist = new List<SelectListItem>();
          ddldepartmentlist.Add(new SelectListItem { Text = "---Select a Department---", Value = "-1", Selected = true });
          if (dtdepartment.Rows.Count > 0)
          {
              for (int i = 0; i < dtdepartment.Rows.Count; i++)
              {
                  ddldepartmentlist.Add(new SelectListItem { Text = dtdepartment.Rows[i]["department"].ToString(), Value = dtdepartment.Rows[i]["departmentID"].ToString() });
              }
          }
          ViewData["ddldepartmentlist"] = ddldepartmentlist;
          return View("_GetEmployeeSpeciality");
      }

IN View

@Html.DropDownList("ddldepartmentlist")

or

@Html.DropDownList("ddldepartmentlist",ViewData["ddldepartmentlist"])

when i run this

There is no ViewData item of type 'IEnumerable<SelectListItem>' that has the key 'ddldepartmentlist'

Error Occurs can anyone helpme.


thanks
parithi

解决方案

you have not cast the viewstate to IEnumerable<SelectListItem> that's why its giving error try this it will work

@Html.DropDownList("ddldepartmentlist",ViewData["ddldepartmentlist"] as IEnumerable<SelectListItem>)

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