Dropdonwlist error

Question

User-543310235 posted

Hi im new on this, i was creating a app MVC 5 VS 2019 a testing program actually, and i got error with saving form, and searching won web and nothing.

Web config

  <connectionStrings>
    <add name="PacienteDBContext"  connectionString="Data Source=(localdb)\MSSQLLocalDB;Initial Catalog=Paciente;Integrated Security=SSPI;AttachDBFilename=|DataDirectory|\Paciente.mdf" providerName="System.Data.SqlClient" />
  </connectionStrings>

model folder -> clDbContext.cs

using System.Data.Entity;

namespace MVC2JPacientes.Models
{
    public class ClDbContext : DbContext
    {
        public ClDbContext()
            : base("PacienteDBContext") //base("DefaultConnection") o base("MircorostConnection")
        {
        }

        public DbSet<Paciente> Pacientes { get; set; }
        public DbSet<Genero> Generos { get; set; }
    }
}

model folder -> genero.cs

using System.ComponentModel.DataAnnotations;

namespace MVC2JPacientes.Models
{
    public class Genero
    {
        [Key]
        public int GeneroId { get; set; }

        [Required]
        public string Nombre { get; set; }
    }
}

model folder -> paciente.cs

using System.ComponentModel.DataAnnotations;

namespace MVC2JPacientes.Models
{

    public class Paciente
    {
                
        [Required]
        [Key]
        public Int64 Id { get; set; }

        [Display(Name = "Nombre del paciente")]
        [Required(ErrorMessage = "Nombre requerido")]
        public string PacienteNombre { get; set; }

        public int? Age { get; set; }

        public decimal? Peso { get; set; }

        public decimal? Masa { get; set; }

        public decimal? Liquido { get; set; }
        
        [Display(Name = "Genero de la persona")]
        [Required(ErrorMessage = "Genero requerido requerido")]
        [Key]
        public Genero Genero_ { get; set; }

        [Required]
        [Display(Name = "Fecha de nacimiento")]
        [DisplayFormat(ApplyFormatInEditMode = true, DataFormatString = "{0:dd/MMM/yyyy}")]
        [DataType(DataType.Date)]
        public DateTime DoB { get; set; }

        [Display(Name = "Email Address:")]
        [Required(ErrorMessage = "The email address is required")]
        [RegularExpression("^[a-zA-Z0-9_\\.-]+@([a-zA-Z0-9-]+\\.)+[a-zA-Z]{2,6}$", ErrorMessage = "E-mail is not valid")]
        public string Email { get; set; }

        public int? Estado { get; set; }

    }

controler folder -> PacienteControler.cs

namespace MVC2JPacientes.Controllers
{
    [RouteArea("Admin")]
    public class PacientesController : Controller
    {
        private ClDbContext db = new ClDbContext();

        public async Task<ActionResult> Index()
        {
            return View(await db.Pacientes.ToListAsync());
        }
        public ActionResult Create()
        {
            //dropdonlist llenar
            using (ClDbContext Tablas = new ClDbContext())
            {
                SelectList genero = new SelectList(Tablas.Generos.OrderBy(x => x.GeneroId).ToList(), "GeneroId", "Nombre");
                ViewBag.Generov_ = genero;
            }
            //dropdonlist llenar
            return View();
        }

        [HttpPost]
        [ValidateAntiForgeryToken]
        public async Task<ActionResult> Create([Bind(Include = "Id,PacienteNombre,Age,Peso,Masa,Liquido,Genero_,DoB,Email,Estado")] Paciente paciente)
        {

            if (ModelState.IsValid)
            {
                db.Pacientes.Add(paciente);
                await db.SaveChangesAsync();
                return RedirectToAction("Index");
            }

            return View(paciente);
        }

folder -> Views-> Paciente -> Create.cshtml

        <div class="form-group">
            @Html.LabelFor(model => model.Genero_, htmlAttributes: new { @class = "control-label col-md-2" })
            <div class="col-md-10">
                @Html.DropDownListFor(model => model.Genero_, new SelectList(ViewBag.Generov_,"Value","Text")  , "Favor de selecionar uno", new { @class = "form-control" })

                @Html.ValidationMessageFor(model => model.Genero_, "", new { @class = "text-danger" })
            </div>
        </div>

but when i save get this error

https://1drv.ms/u/s!AkGgScb34Z8ky06avNBkW_F8y8vg

https://1drv.ms/u/s!AkGgScb34Z8ky083P2qs8ymbNJLh

Thanks in advance!

greetings,

Juan Solares

Answer 1

User-474980206 posted

the dropdown posts its value (GeneroId in your case), but you are try to bind this value to an object. you should add a GeneroId (reference key) to the view model.

       @Html.DropDownListFor(model => model.GeneroId, 
             (SelectList) ViewBag.Generov_,
             "Favor de selecionar uno",
             new { @class = "form-control" }).

Answer 2

User-543310235 posted

Hi,

I tried that, and got an error.

the sugestion:

<div class="col-md-10">
  @Html.DropDownListFor(model =>model.Genero_.GeneroId , (SelectList) ViewBag.Generov_  , "Favor de selecionar uno", new { @class = "form-control" })
  @Html.ValidationMessageFor(model => model.Genero_, "", new { @class = "text-danger" })
</div>

an the error.

https://1drv.ms/u/s!AkGgScb34Z8ky1B_FsDwRzAvGiWR

thanks in advance.

greetings,

Juan Solares

Answer 3

User-474980206 posted

you don't have the model correct.

as I stated you need to add the column (which will be used to link to the Genero table);

     public int GeneroId {get; set;}

to the class Paciente then bind to this new field.

Answer 4

User1686398519 posted

Hi,  jpsolares

You need to set ViewBag.Generov_ in the Create Post method. Your page does not need to be modified.

        private Model1 context = new Model1();
        public SelectList Getgenero()
        {
            SelectList genero = new SelectList(context.Generos.OrderBy(x => x.GeneroId).ToList(), "GeneroId", "Nombre");  
            return genero;
        }
        public async Task<ActionResult> Index()
            {
                return View(await context.Pacientes.ToListAsync());
            }
            public ActionResult Create()
            {
            Paciente paciente = new Paciente();
            //ViewBag.Generov_ = genero;
            ViewBag.Generov_ = Getgenero();

            //dropdonlist llenar
            return View(paciente);
            }

            [HttpPost]
            [ValidateAntiForgeryToken]
            public async Task<ActionResult> Create([Bind(Include = "Id,PacienteNombre,Age,Peso,Masa,Liquido,Genero_,DoB,Email,Estado")] Paciente paciente)
            {
            string DropDownListValue = Request.Form["Genero_"].ToString();
            paciente.Genero_ = new Genero();
            paciente.Genero_.GeneroId = Int32.Parse(DropDownListValue);
            if (ModelState.IsValid)
                {
                context.Pacientes.Add(paciente);
                    await context.SaveChangesAsync();
                    return RedirectToAction("Index");
                }
            ViewBag.Generov_ = Getgenero();
            return View(paciente);
            }

Here is the result.

 
Best Regards,

YihuiSun

Answer 5

User-543310235 posted

Thanks, and is almost, in the model the name is requiered. Generoid and Nombre is required.

thanks in advance.

Juan Solares

Answer 6

User-543310235 posted

Another way is to use the entity framawork doit for u.

public class Paciente2
    {

        [Key]
        public Int64 Id { get; set; }

        [Display(Name = "Nombre del paciente")]
        [Required(ErrorMessage = "Nombre requerido")]
        public string PacienteNombre { get; set; }

        public int Age { get; set; }

        public decimal Peso { get; set; }

        public decimal Masa { get; set; }

        public decimal Liquido { get; set; }
                
        [Required]
        [Display(Name = "Fecha de nacimiento")]
        [DisplayFormat(ApplyFormatInEditMode = true, DataFormatString = "{0:dd/MMM/yyyy}")]
        [DataType(DataType.Date)]
        public DateTime DoB { get; set; }

        [Display(Name = "Email Address:")]
        [Required(ErrorMessage = "The email address is required")]
        [DataType(DataType.EmailAddress)]
        [RegularExpression("^[a-zA-Z0-9_\\.-]+@([a-zA-Z0-9-]+\\.)+[a-zA-Z]{2,6}$", ErrorMessage = "E-mail is not valid")]
        public string Email { get; set; }

        [Display(Name = "Estado")]
        [Required(ErrorMessage = "Estado requerido")]
        public int Estadoid { get; set; }

        //[NotMapped]
        [Display(Name = "Estado")]
        public virtual Estados2 estados { get; set; }

    }

    public class Estados2
    {
        [Key]
        public int EstadoId { get; set; }

        [Required]
        public string Nombre { get; set; }

        public IList<Paciente2> Pacientes_ { get; set; }
    }

Create the controler to doit all, list, create, edit, view and delelte, with this models, and Entity framework doit for u even the drop down list with related data, is hard work to get here, a lot of days searching, at this point i realize what Microsoft says is true u code less :), but only and only if u have the right model, that dosent show u in the microsoft tutorials, and should.

Thanks every one, and my two cents.

Greetings,

Juan Solares