ViewData and ViewBag with example in MVC

ViewData

1. It is used to pass data from controller to view.
2. Data is available only for the current request and it's value becomes null once redirection occurs.
3. Derived from ViewDataDictionary class.
4. It requires typecasting for complex data type and checks for null values to avoid error.

ViewBag

1. It is also used to pass data from controller to view.
2. Data is available only for the current request and it's value becomes null once redirection occurs.
3. It does not required typecasting.
4. It is a dynamic property that takes advantage of the new dynamic features in C# 4.0

Example of ViewBag & ViewData

Step 1 : Create new MVC Project

Step 2 : Change the Name, Location of Project

Step 3 : Choose Empty MVC Application

Step 4 : Create Controller

Step 5 : Put the given Code in Controller

using System;

using System.Collections.Generic;

using System.Linq;

using System.Web;

using System.Web.Mvc;

namespace MVCExample.Controllers

{

    public class HomeController : Controller

    {

        //

        // GET: /Home/

        public ActionResult Index()

        {

            ViewBag.Sports = new List<String>()

            {

                "Cricket",

                "Football",

                "Volleyball",

                "Basetball"

            };

            return View(ViewBag);

        }

        public ActionResult UsingViewData()

        {

            ViewData["Sports"] = new List<String>()

            {

                "Cricket",

                "Football",

                "Volleyball",

                "Basetball"

            };

            return View(ViewData);

        }

       }

}

Step 6 : Right click index, UsingViewData method of return type ActionResult to add two views. One for ViewBag and other for ViewData.

Step 7 : Index view will be created in Home Folder inside Views Folder.

Put the following code in View

In Index.cshtml

@{

    ViewBag.Title = "Sports";

}

<h2>Sports</h2>

<ol>

    @foreach (string strSports in ViewBag.Sports)

    {

        <li>

            @strSports

        </li>

    }

</ol>

In UsingViewData.cshtml

@{

    ViewBag.Title = "UsingViewData";

}

<h2>Sports with ViewData</h2>

<ol>

    @foreach (string strSports in (List<String>)ViewData["Sports"])

    {

        <li>

            @strSports

        </li>

    }

</ol>

Step 8 : Run the Application