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Accepted
Richard Víquez Pérez
Asked: 2020-10-16 10:16:43 +0800 CST 2020-10-16 10:16:43 +0800 CST

How to get the value of a dropdownlist at checkin with Asp.Net Framework MVC

  • 772

In my user registry controller I have the following 

   [AllowAnonymous]
   public ActionResult Register()
   {    
      var categorias = db.Categoria.ToList().Where(x=>x.Estado);    
      var list = new SelectList(categorias, "Codigo", "Descripcion");

      ViewData["categorias"] = list;    
      ViewBag.Drop= new SelectList(categorias, "Codigo", "Descripcion");
      return View();
   }

This correctly fills me a DropDownList when loading the view. However, when I try to register, that is, when I try to save the data in the database, it gives me the following error:

enter image description here

The code to save to the database or method POSTis as follows: 

// POST: /Account/Register
   [HttpPost]
   [AllowAnonymous]
   [ValidateAntiForgeryToken]
   public async Task<ActionResult> Register(RegisterViewModel model, HttpPostedFileBase upload)
   {
      ApplicationUser user = new ApplicationUser();
      byte[] foto;
      string categ = model.Categoria;

      if (ModelState.IsValid)
      {         
         if (upload != null && upload.ContentLength > 0)
         {
            using (var reader = new System.IO.BinaryReader(upload.InputStream))
            {
               foto = reader.ReadBytes(upload.ContentLength);
            }

            user = new ApplicationUser
            {
               UserName = model.Email,
               Email = model.Email,
               Hometown = model.Hometown,
               Direccion = model.Direccion,
               NombreComercial = model.NombreComercial,
               Tipo = "Comercio",
               Estado = true,
               Foto = foto,
               Link = model.Link,
               Cedula = model.Cedula,
               Categoria= categ
            };
         }
         else
         {
            user = new ApplicationUser
            {
               UserName = model.Email,
               Email = model.Email,
               Hometown = model.Hometown,
               Direccion = model.Direccion,
               NombreComercial = model.NombreComercial,
               Tipo = "Comercio",
               Estado = true,
               Foto = model.Foto,
               Link = model.Link,
               Cedula = model.Cedula,
               Categoria = categ
            };
         }

         var result = await UserManager.CreateAsync(user, model.Password);

         if (result.Succeeded)
         {
            await SignInManager.SignInAsync(user, isPersistent: false, rememberBrowser: false);       
            return RedirectToAction("Index", "Home");
         }
         AddErrors(result);
      }     
      return View(model);
   }
c#

1 Answers

  1. Best Answer

    The problem you have is when you try to create the Model UserManager.CreateAsync(user, model.Password) without success .

    So your Register[HttpPost] Action returns you to the View Register.cshtmlwith the Model RegisterViewModel:

    return View(model);

    Once in the View, it tries to create the but the with the categories DropDownListFor()no longer exists . ViewData["categorias"]So you should recreate it before calling the View:

    var categorias = db.Categoria.ToList().Where(x=>x.Estado);
var list = new SelectList(categorias, "Codigo", "Descripcion");
ViewData["categorias"] = list;
// Ahora si puedes llamar a la Vista.
return View(model);
    • 1