Need clarification for using linq in asp.net mvc apps

Question

I have method to retrieve data from DAL as follows:

public List<Comment> GetAllComment(int _UserID)
    {
        using (var context = new TourBlogEntities1())
        {
            var AllComment = from s in context.Comments
                             where s.UserID == _UserID
                             select s;

            return AllComment.ToList<Comment>();
        }
    }

Now I'm trying to call this method from my controller as follwos:

[HttpPost]
    public ActionResult NewComment(PostComment model)
    {
        var business = new Business();

        var entity = new Comment();
        entity.Comments = model.Comments.Comments;
        //entity.PostID = model.Posts.PostID; HOW TO PASS POSTID???
        entity.UserID = business.GetUserID(User.Identity.Name);

        business.PostComment(entity);

        var CommentsListFromEntity = business.GetAllComment(business.GetUserID(User.Identity.Name));

        var viewmodel = new PostComment();
        viewmodel.CommentsListFromModel = CommentsListFromEntity.ToList<CommentInfo>(); // Error is showing here  

        return View("ViewPost", viewmodel);
    }

I bind my view with the model, but could not use the list, Even if I try to pass the list itself to view, still I can't use that list in view!

My model class is as follows:

public class PostComment
{
    public PostComment()
    {
        Posts = new NewPost();
        Comments = new CommentInfo();
        User = new UserInfoModel();
    }

    public NewPost Posts { get; set; }
    public CommentInfo Comments { get; set; }
    public UserInfoModel User { get; set; }
    public List<CommentInfo> CommentsListFromModel { get; set; }

}

So how to use the list in view? I need the help badly!

Answer 1

You need to return an ActionResult from controller actions:

public ActionResult GetAllComment(int _UserID)
{
    using (var context = new TourBlogEntities1())
    {
        var AllComment = from s in context.Comments
                         where s.UserID == _UserID
                         select s;

        return View(AllComment.ToList());
    }
}

Now the corresponding view could be strongly typed to List<Comment>:

@model List<Comment

and then you could loop through the model and display it:

@foreach (var comment in Model) 
{
    <div><@comment.Text</div>
}

---

UPDATE:

If this method is in your BLL you could invoke it in your controller action and pass the result to the view:

public ActionResult SomeAction(int userID)
{
    List<Comment> comments = bll.GetAllComment(userID);
    return View(comments);
}

---

UPDATE 2:

If you need to pass other properties to the view in addition to this list then you define a view model containing all the necessary information:

public class MyViewModel
{
    public List<Comment> Comments { get; set; }
    public string Foo { get; set; }
    public string Bar { get; set; }
    ...
}

and then have your controller action pass this view model to the view:

public ActionResult SomeAction(int userID)
{
    var model = new MyViewModel();
    model.Comments = bll.GetAllComment(userID);
    model.Foo = "that's the foo";
    model.Bar = "that's the bar";
    return View(model);
}

and finally your view is strongly typed to the new view model:

@model MyViewModel

<h2>@Html.DisplayFor(x => x.Foo)</h2>

@foreach (var comment in Model.Comments)
{
    <div>@comment.Text</div>
}

<span>@Html.DisplayFor(x => x.Bar)</span>