Question

I’am using ASP.NET MVC 4 with EF, I have a PostController with the Index and Create views. I would like to have both on the same page for adding a post, and visualize it on the same page. How can I do it ?

Thanks for your advices

___EDIT__

Controller :

        public ActionResult Index()
        {
            return View(db.Posts.ToList());
        }

        [HttpGet]
        public ActionResult Create()
        {
            return PartialView("_Create", **Here I can't declare model**);
        }

        [HttpPost]
        public ActionResult Create(FormCollection values)
        {
            var post = new Post();
            TryUpdateModel(post);

            if (ModelState.IsValid)
            {
                /** somme code **/

                db.Posts.Add(post);
                db.SaveChanges();
                return RedirectToAction("Index");
            }
            return View("_Create", post);
        }

My _Create partial view :

@model MyProject.Models.Post

<h2>Create</h2>

@using (Html.BeginForm()) {
    @Html.ValidationSummary(true)

    /**some stuff **/
}

my Index View :

@model IEnumerable<MyProject.Models.Post>

@{
    ViewBag.Title = "Index";
}

<p>
    /** some stuff **/
</p>

@Html.Partial("_Create", **Here I can't declare model**)

And my Post Model :

public int PostId { get; set; }    
public int UserId { get; set; }       
public string Content { get; set; }

It tells me that “The model item passed into the dictionary is of type ‘System.Collections.Generic.List`1[MyProject.Models.Post]’ but this dictionary requires a model item of type ‘MyProject.Models.Post‘.

Answer 1

It really depends on how your code looks right now. If you have a separate Create action method returning a PartialView, like so:

[HttpGet]
public ActionResult Create()
{
    // Do stuff here to populate your model, if necessary
    return PartialView("_Create", model);
}

Then in your view you would use Html.RenderAction() where you want the _Create partial view to be displayed:

<div id="IndexViewStuff">
    <p>Some stuff in your normal Index view.</p>
    @{Html.RenderAction("Create", "Post");}
</div>

If you don’t have a separate action method for Create and just have a partial view to make things cleaner, then simply using Html.Partial() in your Index view will do the trick:

@Html.Partial("_Create") // If your _Create partial does not require a model
@Html.Partial("_Create", Model.CreateViewModel) // If it does require a model

Update

After looking through your code, there are two ways you can do it (I’ll show you both). Your problem occurs because you’re passing a list of posts to your Index view while your _Create partial view requires a single Post model. Since you aren’t explicitly passing a model to the partial view when you’re calling it, it automatically tries to use the model in the Index view (your list of posts). The first way to solve the problem requires minimal changes to your code.

Change your Create action method as follows:

[HttpGet]
public ActionResult Create()
{
    // You have to pass a new Post
    return PartialView("_Create", new MyProject.Models.Post());
}

Then in your Index view, use:

@{Html.RenderAction("Create", "Post");}

The second method is to use a view model that exposes the list of posts to display on the Index view, and also has an “empty” Post model that can be used to create a new post in the _Create partial view. I prefer this method, but it’s your call.

Your view model:

public class MyViewModel
{
    public IEnumerable<Post> Posts { get; set; }
    public Post CreatePost { get; set; }
}

Your Index action method:

public ActionResult Index()
{
    MyViewModel model = new MyViewModel()
    {
        Posts = db.Posts.ToList(),
        CreatePost = new MyProject.Models.Post()
    };

    return View(model);
}

Your Index view:

@model The.Namespace.MyViewModel

@{
    ViewBag.Title = "Index";
}

@foreach (var post in Model.Posts)
{
    <p>post.Content</p> // Or however you want to display your posts
}

@Html.Partial("_Create", Model.CreatePost) // Pass the correct model

Your _Create partial view will remain the same.