Question

I am trying to teach myself C# and MVC 3.

I am learning by creating a simple blog application. I am stuck at detail page of the blog. This page displays the post and it works fine – that is, displays the post and the comments on the post. However, I want to add a form to add new comments.

I think the way to do that is to create a viewmodel which contains both blog and comment class and then I should be able to create a comment form which calls create action of comment controller.

However, when I do that the blog display page doesnt show up becasue it expects a model of type ‘BlogDetailViewModel’. I guess that is because the ‘Details’ action of ‘Blog’ controller is passing a ‘blog’ model to the view and not ‘BlogDetailViewModel’. How do I correct this error.

Is this the best way to deal with this issue.

I am detailing all the code below:

Blog Controller – Details Method

public ViewResult Details(int id)
{

    Blog blog = db.Blogs.Find(id);
    return View(blog);
}

Blog.cs

 public class Blog
    {
        public int BlogID { get; set; }
        public string Title { get; set; }
        public string Writer { get; set; }

        [DataType(DataType.MultilineText)]
        public string Excerpt { get; set; }

        [DataType(DataType.MultilineText)]
        public string Content { get; set; }

        [DataType(DataType.Date)]
        public DateTime PublishDate { get; set; }

        public virtual ICollection<Comment> Comments { get; set; }
    }

Comment.cs

 public class Comment
    {
        public int CommentID { get; set; }
        public string Name { get; set; }

        [DataType(DataType.EmailAddress)]
        public string Email { get; set; }

        [DataType(DataType.MultilineText)]
        public string CommentBody { get; set; }

        public int BlogID { get; set; } 
        public virtual Blog Blog { get; set; }
    }

BlogDetailViewModel.cs

public BlogDetailViewModel
{
    public Blog Blog{ get; set; }
    public Comment comment{ get; set; }
}

Blog Details View

@model NPLHBlog.ViewModels.BlogDetailViewModel

@{
    ViewBag.Title = @Model.Blog.Title;
}

….

I have tried to comment everything out of blog details view and just keep the title. However, even that doesn’t work.

Any help would be grateful.

Answer 1

The type passed to View() in your controller must match the @model type in your view.

public ViewResult Details(int id)
{
    Blog blog = db.Blogs.Find(id);
    BlogDetailViewModel viewModel = new BlogDetailViewModel {Blog = blog, Comment = ""};
    return View(viewModel);
}