asp.net mvc dropdownlist綁定

下面是我的模型。我創建在MVC表下拉列表中，但我得到這個錯誤asp.net mvc dropdownlist綁定

public class UserRegisterModel 
{ 
    [Required] 
    [Display(Name = "User name")] 
    public string UserName { get; set; } 

    [Required] 
    [DataType(DataType.Password)] 
    [Display(Name = "Password")] 
    public string Password { get; set; } 

    public IEnumerable<Role> Roles { get; set; } 
    public SelectList RoleSelectList { get; set; } 
    public Role Role { get; set; } 

    private List<Role> GetRoles() 
    { 
     List<Role> roles = new List<Role>(); 

     roles.Add(new Role() { Value = "c", RoleCode = "Corporate" }); 
     roles.Add(new Role() { Value = "d", RoleCode = "Divisional" }); 
     roles.Add(new Role() { Value = "r", RoleCode = "Regional" }); 
     roles.Add(new Role() { Value = "f", RoleCode = "Facility" }); 
     roles.Add(new Role() { Value = "s", RoleCode = "Resource" }); 
     return roles; 
    } 

    public UserRegisterModel() 
    { 
     this.Roles = GetRoles(); 
     this.RoleSelectList = new SelectList(Roles, "Value", "RoleCode"); 
    } 


    public IEnumerable<UserAccinfo> UserAccounts { get; set; } 

} 
public class UserAccinfo 
{ 
    public string accountno { get; set; } 
    public IEnumerable<Brand> Brands { get; set; } 
    public SelectList BrandSelectList { get; set; } 
    public Brand Brand { get; set; } 

    private List<Brand> GetBrands() 
    { 
     List<Brand> brands = new List<Brand>(); 

     brands.Add(new Brand() { BrandValue = "c", BrandCode = "Corporate" }); 
     brands.Add(new Brand() { BrandValue = "d", BrandCode = "Divisional" }); 
     brands.Add(new Brand() { BrandValue = "r", BrandCode = "Regional" }); 
     brands.Add(new Brand() { BrandValue = "f", BrandCode = "Facility" }); 
     brands.Add(new Brand() { BrandValue = "s", BrandCode = "Resource" }); 
     return brands; 
    } 

    public UserAccinfo() 
    { 
     this.Brands = GetBrands(); 
     this.BrandSelectList = new SelectList(Brands, "BrandValue", "BrandCode"); 
    } 
} 
public class Brand 
{ 
    public string BrandCode { get; set; } 
    public string BrandValue { get; set; } 
} 
public class Role 
{ 
    public string RoleCode { get; set; } 
    public string Value { get; set; } 
}

我如何可以綁定在MVC視圖第二下拉列表？

來源

2012-12-20 user1913029

您可以添加您收到的錯誤嗎？ – glosrob

這是錯誤消息：方法'System.Web.Mvc.Html.SelectExtensions.DropDownListFor （System.Web.Mvc.HtmlHelper ，System.Linq.Expressions.Expression >，System.Collections.Generic.IEnumerable ，string，object）'不能從用法中推斷出來。嘗試明確指定類型參數。 – user1913029

我正在做這樣的考慮：

@foreach（VAR貓Model.UserAccounts） { @ Html.DropDownListFor（cat.Brand.BrandValue，cat.BrandSelectList 「 - 選擇 - 」空）@ cat.accountno }

– user1913029

在控制器：

public ActionResult Index() 
{ 
     UserRegisterModel UserRegisterModel = new UserRegisterModel(); 
     UserAccinfo UserAccinfo = new UserAccinfo(); 

     ViewBag.Brands = UserAccinfo.BrandSelectList; 
     ViewBag.Roles = UserRegisterModel.RoleSelectList; 
     return View(); 
}

和Index.cshtml

@Html.DropDownList("Brands"); 
@Html.DropDownList("Roles");

如果選擇品牌你可以做到這一點時，想要改變角色。

在控制器中添加JsonResult：

public JsonResult LoadRoles(string v) 
    { 
     UserRegisterModel UserRegisterModel = new UserRegisterModel(); 
     List<KeyValuePair<string, string>> items = new List<KeyValuePair<string, string>>(); 
     if (!string.IsNullOrWhiteSpace(v)) 
     { 
      var roles = UserRegisterModel.RoleSelectList.Where(x => x.Value == v); 
      if (roles.Count() > 0) 
      { 
       foreach (var r in roles) 
       { 
        items.Add(new KeyValuePair<string, string>(r.Value,r.Text)); 
       } 
      } 
     } 
     return Json(items); 
    }

Index.cshtml

<script> 

    $(function() { 
     //When Brands change 
     $("#Brands").change(function() { 
      $.ajax({ 
       //Call postback 
       url: '@Url.Action("LoadRoles", "Home")', 
       data: { v: $(this).val() }, 
       type: 'post', 
       cache: false, 
       dataType: 'json', 
       success: function (data) { 
        if (data.length > 0) { 
         $('#Roles').empty(); 
         //add result to downlist 
         $.each(data, function (i, item) { 
          $('#Roles').append($('<option></option>').val(item.Key).text(item.Value)); 
         }); 
        } 
       } 
      }); 
     }); 
    }); 
</script>

來源

2016-07-06 05:42:40 user2971963

public ActionResult AllUsers() { 
    List<Users> users = userRep.GetUsers(); 
    var listUsers = (from u in users.AsEnumerable() 
         select new SelectListItem 
         { 
         Text = u.UserName, 
         Value = u.UserId.ToString(), 
         Selected = (u.UserId==6) 
         }).AsEnumerable(); 
    // ViewBag.ListItems = listUsers; 
    ViewData["tempEmpList"]=listUsers 
    //ViewBag.SelectedItem = 2; 
     return View(); }

上查看

@ Html.DropDownList（「SelectedEmployee」，新的SelectList（（IEnumerable的）ViewData [「tempEmpList」]，「Id」，「Name」））**

來源

2016-12-15 08:49:27

asp.net mvc dropdownlist綁定

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