Dynamic V Strongly Typed Views


There are three ways to pass information from a controller to a view in ASP.NET MVC 3:

  1. As a strongly typed model object.
  2. As a dynamic type (using @model dynamic)
  3. Using the ViewBag

I’ve written a simple MVC 3  Top Blog application to compare and contrast dynamic and strongly typed views. The controller starts out with a simple list of blogs:

using System.Collections.Generic;
using System.Web.Mvc;

namespace Mvc3ViewDemo.Controllers {

    public class Blog {
        public string Name;
        public string URL;
    }

    public class HomeController : Controller {

        List<Blog> topBlogs = new List<Blog>
      { 
new Blog { Name = "ScottGu", URL = "http://weblogs.asp.net/scottgu/"},
new Blog { Name = "Jon Galloway", URL = "http://weblogs.asp.net/jgalloway"},
new Blog { Name = "Scott Hanselman", URL = "http://www.hanselman.com/blog/"}
      };

        public ActionResult IndexNotStonglyTyped() {
            return View(topBlogs);
        }

        public ActionResult StonglyTypedIndex() {
            return View(topBlogs);
        }

        public ActionResult IndexViewBag() {
            ViewBag.BestBlogs = topBlogs;
            return View();
        }
    }
}

Right-click in the IndexNotStonglyTyped() method and add a Razor view.

alt

Make sure the Create a strongly-typed view box is not checked. The resulting view doesn’t contain much:

@{
    ViewBag.Title = "IndexNotStonglyTyped";
}

<h2>IndexNotStonglyTyped</h2>

On the first line of the Views\Home\IndexNotStonglyTyped.cshtml file, add the model directive and
the dynamic keyword.

@model dynamic

Because we’re using a dynamic and not a strongly typed view, intellisense doesn’t help us. The completed code is shown below:

@model dynamic
           
@{
    ViewBag.Title = "IndexNotStonglyTyped";
}

<h2>Index Not Stongly Typed</h2>

<p>
 <ul>
@foreach (var blog in Model) {
   <li>
    <a href="@blog.URL">@blog.Name</a>
   </li>   
}
 </ul>
</p>

alt

Now we’ll add a strongly typed view. Add the following code to the controller:

public ActionResult StonglyTypedIndex() {
    return View(topBlogs);
}

Notice it’s exactly the same return View(topBlogs); call as the non-strongly typed view. Right click inside of StonglyTypedIndex() and select Add View. This time select the Blog Model class and select List as the Scaffold template.

alt

Inside the new view template we get intellisense support and our view model is automatically scaffolded. Those are significant advantages and why ASP.NET MVC applications typically use strongly typed views. Strongly-typed view gives you:

alt

Another non-strongly typed way we can pass the top blogs into a view template is to use the view bag.  ViewBag is new to MVC 3 and has the advantage that it can be used in combination with a strongly typed model, giving you the advantages for both. ViewBag is useful when you want to pass information not related to the view model and you don’t want to create a view model just to pass the information. For example, you can use it to pass information to your layout template. Be sure to read ScottGu’s post where he talks about ViewBag.

Add the following action method to the controller:

public ActionResult IndexViewBag() {
            ViewBag.BestBlogs = topBlogs;
            return View();
        }

The IndexViewBag.cshtml view template :

@{
    ViewBag.Title = "Index_ViewBag";
}

<h2>Index View Bag</h2>

<p>
 <ul>
@foreach (var blog in ViewBag.BestBlogs) {
   <li>
    <a href="@blog.URL">@blog.Name</a>
   </li>   
}
 </ul>
</p>

Good ViewBag links:

The c# project can be downloaded here.


Comments (18)

  1. Bugeo says:

    IMHO viewBad don't give the same advantage of strongly typed view.

    It's a shortcut for the viewdDictionary.

  2. Greg says:

    Great post. I just started learning asp.net mvc and this info on how to pass data to views using the razor syntax has been very helpful.

  3. Anuj says:

    Well I would say that it's an all in one complete post.

    Thanks.

  4. --steve... says:

    +3 to Rick's right clicking and +1 to Bugeo's typos. priceless to bot

  5. Bruno says:

    Very nice and useful explanation! Thanks cheers from Portugal!

  6. sagar says:

    hi, good post and very well explained . check also some samples on below link

    paradise-coding.blogspot.com/…/mvc-strongly-typed-view.html

  7. shawn says:

    the link to turning on Compile time type checking is bad – find the article here: devermind.wordpress.com/…/aspnet-mvc-tip-turn-on-compile-time-view-checking

  8. tun says:

    Very simple and useful explanation! Thanks.

    Cheers

  9. anindya says:

    this guy sure knows his stuff right!

  10. Meekrobot says:

    Since its been a few years since you posted this article you probably have long forgotten about it lol, but I would like to point out that the "Compile time type checking"  appears to be a dead link.

  11. This is Really good  thanks ,

    Rick_Anderson

  12. Manas says:

    Thanks very much. It is nice descriptive and easy to understand how to send data from controller to view in different ways. We can implement as per our requirement.

  13. vignesh says:

    Thank u very much Rickandy…. It's very useful and easy to understand for begineers

  14. Ravi K says:

    Really very good post.But i have one question, We can also share data through ViewData to View.I think so this option is missed.

  15. Sadanand says:

    Great Post. But, i have a doubt, which one is better to use?

  16. Talal Aslam says:

    A Great way to Learn. This man has both, knowledge and skill to deliver

  17. Don Heuvelmane says:

    So I'm reading this a few years later and I'm curious why nobody stumbled upon the 'IndexNotStonglyTyped' typo?

    It is consistent I have to give you that.. but the missing 'r' (stRongly) is really getting me of my game.. haha 🙂

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