MVC3 Dropdownlist problem RSS

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  totti_acmila...

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  37 Points

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  MVC3 Dropdownlist problem

  Feb 02, 2012 09:48 AM|LINK

  Actually i am beginner in mvc and web programming so i have an error please help me i used viewbag
  it works fine and also when i submit the values it store in my database but i got this error and i can't understand it please help me :
  **The ViewData item that has the key 'CategoryId' is of type 'System.Byte' but must be of type 'IEnumerable<SelectListItem>'.**
  

  in this line of my view :   

  @Html.DropDownList("CategoryId" , (SelectList)ViewBag.Cat , "--Select One--")

  • Edited by totti_acmilan17 on Feb 02, 2012 09:51 AM
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  totti_acmila...

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  Re: MVC3 Dropdownlist problem

  Feb 02, 2012 09:56 AM|LINK

  this is my model:

   

  public class AddLink
      {
  
  
          [Required]
          [Display(Name = "Url")]
          [DataType(DataType.Url)]
          public string Url { get; set; }
  
  
          [Display(Name = "Title")]
          public String  Title { get; set; }
  
          [Display(Name = "ExpireDate")]
          public DateTime  ExpireDate { get; set; }
  
  
          [Display(Name = "Category")]
          public byte CategoryId { get; set; }
       
  
          [Display(Name = "SubCategory")]
          public byte SubCategoryId { get; set; }
  
     
      }

   

  and 

  this is my controller:

   

   

   

     // GET: /Link/Create
  
          public ActionResult Create()
          {
  
  
              ViewBag.Cat = new SelectList(db.Categories, "CategoryId","Title") ;
              ViewBag.SubCat = new SelectList(db.SubCategories , "SubCategoryId", "Title");
  
  
  
  
              return View();
          }
  
          //
          // POST: /Link/Create
  
          [HttpPost]
          public ActionResult Create(AddLink  link)
          {
             
              if (ModelState.IsValid)
              {
  
             
                  Link l = new Link();
               
                  l.Url  = link.Url ;
                  l.Title  = link.Title ;
                  l.CreationDate  = System.DateTime.Now;
              
                  l.Hit = 0;
                  l.Rate = 0;
                  l.MemberId = int.Parse(@User.Identity.Name.Split('|')[0]);
                  l.CategoryId = System.Convert.ToByte ( link.CategoryId);
                  l.SubCategoryId=link.SubCategoryId ;
                  l.LanguageId = 1;
  
                  LinkDirectoryEntities db = new LinkDirectoryEntities();
                  int u = db.Links.Where(x => x.Title == link.Title).Count();
                  if (u == 0)
                  {
                  
                      db.Links.Add(l);
                      db.SaveChanges();
                  }
  
                  else
                  {
                      ModelState.AddModelError("", "The current Url exist!");
                  }
  
  
                  
              }
              return View(link);
          }

   

  and finally this is my view:

   @model LinkDirectory.Models.Link.AddLink  
          
    
  @{
      ViewBag.Title = "Create";
  }
  
  <h2>Create</h2>
  
  <script src="@Url.Content("~/Scripts/jquery.validate.min.js")" type="text/javascript"></script>
  <script src="@Url.Content("~/Scripts/jquery.validate.unobtrusive.min.js")" type="text/javascript"></script>
  
  @using (Html.BeginForm())
  {
      @Html.ValidationSummary(true)
      <fieldset>
          <legend>Link</legend>
  
          <div class="editor-label">
              @Html.LabelFor(model => model.Url)
          </div>
          <div class="editor-field">
              @Html.EditorFor(model => model.Url)
              @Html.ValidationMessageFor(model => model.Url)
          </div>
  
          <div class="editor-label">
              @Html.LabelFor(model => model.Title)
          </div>
          <div class="editor-field">
              @Html.EditorFor(model => model.Title)
              @Html.ValidationMessageFor(model => model.Title)
          </div>
  
              <div class="editor-label">
              @Html.LabelFor(model => model)
          </div>
  
              <div class="editor-label">
              @Html.LabelFor(model => model.CategoryId)
          </div>
       <div class="editor-label">
  @Html.DropDownList("CategoryId" , (SelectList)ViewBag.Cat , "--Select One--")
      
             
             </div> 
              <div class="editor-label">
              @Html.LabelFor(model => model.SubCategoryId)
          </div>
       <div class="editor-label">
  @Html.DropDownList("SubCategoryId", (SelectList)ViewBag.SubCat , "--Select One--")
  </div>
  
  
          <p>
              <input type="submit" value="Create" />
          </p>
      </fieldset>
  }
  
  <div>
      @Html.ActionLink("Back to List", "Index")
  </div>
  

   

  So,in bolded line in view i got follow error even the code works fine and i got new record in my database

  The ViewData item that has the key 'CategoryId' is of type 'System.Byte' but must be of type 'IEnumerable<SelectListItem>'.

  • Edited by totti_acmilan17 on Feb 02, 2012 09:58 AM
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  raduenuca

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  Re: MVC3 Dropdownlist problem

  Feb 02, 2012 10:31 AM|LINK

  this happens in the HttpPost Create action right? When you return the view again: return View(link);

  You need to call

  ViewBag.Cat = new SelectList(db.Categories, "CategoryId","Title") ;
              ViewBag.SubCat = new SelectList(db.SubCategories , "SubCategoryId", "Title");

  again before return View(link);
  
  

   

  Please click 'Mark as Answer' if my reply has assisted you
  
  Radu Enuca | Blog
  • Edited by totti_acmilan17 on Feb 02, 2012 10:45 AM
  • Edited by totti_acmilan17 on Feb 02, 2012 11:15 AM
  • Marked as answer by ricka6 on Feb 02, 2012 07:14 PM
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  totti_acmila...

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  37 Points

  30 Posts

  Re: MVC3 Dropdownlist problem

  Feb 02, 2012 10:48 AM|LINK

  thank you so much dear Mr.Raduenuca

  it resolved.

  my next problem is :how to relate this two dropdown box to eachother

  i mean when i select value in first combo

  next cobmo values automatically loaded ?

  for example first combo is country and second one is cities

  but i want do that with my codes not new code

  thanks

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  raduenuca

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  Re: MVC3 Dropdownlist problem

  Feb 02, 2012 10:54 AM|LINK

  You can follow this tutorial. It covers more than one way to cascade dropdown lists.

  Please click 'Mark as Answer' if my reply has assisted you
  
  Radu Enuca | Blog
  • Marked as answer by ricka6 on Feb 02, 2012 07:14 PM
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  totti_acmila...

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  37 Points

  30 Posts

  Re: MVC3 Dropdownlist problem

  Feb 02, 2012 11:00 AM|LINK

  Actually i dont want to change my codes i am just looking for simple way.

  because i am amature in web programming and mvc and i checked your page before but i couldn't get too much

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  totti_acmila...

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  37 Points

  30 Posts

  Re: MVC3 Dropdownlist problem

  Feb 02, 2012 12:40 PM|LINK

  any suggestion please ?????

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  ryanw51

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  2363 Points

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  Re: MVC3 Dropdownlist problem

  Feb 02, 2012 12:44 PM|LINK

  There really isn't an easier way to do it.  You'll have to use an ajax call or some custom JS to accomplish cascading select lists.  Sometimes when I'm feeling lazy, Ill make an ajax call that returns a partial view containing an entire new list and replace the old list.

  • Edited by ryanw51 on Feb 02, 2012 12:47 PM
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  Yorrick vd V...

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  Re: MVC3 Dropdownlist problem

  Feb 02, 2012 12:46 PM|LINK

  Hi,

   

  Pls take a look at the following post, maybe it will help you on your way:

  • http://forums.asp.net/t/1748239.aspx/1?Cascading+drop+downs+from+database+table+rows

  You can download a working example project from here: https://skydrive.live.com/?cid=2bfae4e91bf38268#cid=2BFAE4E91BF38268&id=2BFAE4E91BF38268%21128

  Download the CascadedDdl.zip file.

  Hope this helps.

  Regards,

  Yorrick

  Live life loosely coupled and separated of concerns
  &
  Don't forget to click "Mark As Answer" on the post that helped you.
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  stevenbey

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  Re: MVC3 Dropdownlist problem

  Feb 02, 2012 12:50 PM|LINK

  totti_acmilan17

  thank you so much dear Mr.Raduenuca

  it resolved.

  my next problem is :how to relate this two dropdown box to eachother

  Really, you should have marked Radu's post as the answer and created a new thread.  Not only does it give Radu the points he deserves but helps other people, with the same problem, find the answer.

  Steven Bey
  http://stevenbey.com
  
  Recursion: see Recursion