MVC ASP.NET中的错误404。 查看不显示

Question

Im having trouble creating a view and its own actionresult. The error that I get is this one

Error de servidor en la aplicación '/'.

No se encuentra el recurso.

Descripción: HTTP 404. El recurso que está buscando (o una de sus dependencias) se puede haber quitado, haber cambiado de nombre o no estar disponible temporalmente. Revise la dirección URL siguiente y asegúrese de que está escrita correctamente.

Dirección URL solicitada: /Cursos/AgregarAlumno/2

This is my view (I know its unfinished, but I think thats not the problem)

@model LibreriaEntidad.Cursos
@{
    ViewBag.Title = "AgregarAlumnos";
}

<h2>AgregarAlumnos</h2>

@using (Html.BeginForm())
{
    <fieldset>
        <legend>Cursos</legend>

        @*<div class="editor-label">
            @Html.LabelFor(model => model.idCurso)
        </div>
        <div class="editor-field">
            @Html.EditorFor(model => model.idCurso)
            @Html.ValidationMessageFor(model => model.idCurso)
        </div>*@

        <div class="editor-label">
            @Html.LabelFor(model => model.Nombre)
        </div>
        <div class="editor-field">
            @Html.EditorFor(model => model.Nombre)
            @Html.ValidationMessageFor(model => model.Nombre)
        </div>

        <div class="editor-label">
            @Html.LabelFor(model => model.idReparticion)
        </div>
        <div class="editor-field">
            @Html.EditorFor(model => model.idReparticion)
            @Html.ValidationMessageFor(model => model.idReparticion)
        </div>

        @*<div class="editor-label">
            @Html.LabelFor(model => model.Presencual)
        </div>
        <div class="editor-field">
            @Html.EditorFor(model => model.Presencual)
            @Html.ValidationMessageFor(model => model.Presencual)
        </div>

        <div class="editor-label">
            @Html.LabelFor(model => model.Virtual)
        </div>
        <div class="editor-field">
            @Html.EditorFor(model => model.Virtual)
            @Html.ValidationMessageFor(model => model.Virtual)
        </div>*@

            <div class="editor-field">
                @Html.DropDownList("idUsuario", ViewBag.Usuarios as SelectList)
            </div>
            <p>
                <input type="submit" value="Save" />
            </p>
</fieldset>

and my controller action over here.

[HttpPost]
[ValidateAntiForgeryToken]
public ActionResult AgregarAlumnos(int id = 0)
{
    Cursos cursos = db.Cursos.Find(id);
    ViewBag.Usuarios = new SelectList(db.Usuario, "idUsuario", "Nombre");
    return View(cursos);
}

Thanks in advance

Answer 1

You should remove [HttpPost] attributes from your action.

Update:

To display view the action must accept the GET request. You should use two different actions for displaying view and submitting form.

Answer 2

You need a corresponding HttpGet method, as your current one only accepts a HttpPost request. Add the following:

[HttpPost]
public ActionResult AgregarAlumnos(int id = 0)
{
    Cursos cursos = db.Cursos.Find(id);
    ViewBag.Usuarios = new SelectList(db.Usuario, "idUsuario", "Nombre");
    return View(cursos);
}

HttpGet:- Whenever any View loads first time HttpGet method executes. That means on first request for any URL in Asp.Net MVC HttpGet method executes. That means if any URL receives the input through URL we can handle the input through HttpGet method.

HttpPost:- HttpPost method executes once you click on Submit button in MVC form. That means we can process the form data by using HttpPost method.