Similarities & Differences Between ViewData And ViewBag In ASP.Net MVC

Similarities Between ViewData And ViewBag In ASP.Net MVC

• Both ViewData and ViewBag are used to pass data from a controller to a view.
• Both Helps to maintain data when you move from controller to view.
• Short life means value becomes null when redirection occurs.
• ViewData and ViewBag are DataDictionary objects.
• Both ViewData and ViewBag does not provide compile time error checking. For Example– if you mis-spell keys you wouldn’t get any compile time errors. You get to know about the error only at runtime.

Differences Between ViewData And ViewBag In ASP.Net MVC

Note: To pass data from controller to a view, it’s always a good practice to use strongly typed view models over ViewBag and ViewData. Strongly typed view models provide compile time error checking.

Source Code Of HomeController

using Difference_ViewBag_Viewdata.Models;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.Mvc;

namespace Difference_ViewBag_Viewdata.Controllers
{
    public class HomeController : Controller
    {
        // GET: Home
        public ActionResult Index()
        {
            ViewData["Message1"] = "Data comes form ViewData";
            ViewBag.Message2 = "Data comes form ViewBag";

            ViewData["CurrentDate1"] = DateTime.Now.ToString();
            ViewBag.CurrentDate2 = DateTime.Now.ToString();

            string[] games = {"Hockey","Football","Cricket","Baseball" };

            ViewData["GamesArray1"] = games;
            ViewBag.GamesArray2 = games;

            Employee Asim = new Employee();
            Asim.Empid = 11;
            Asim.EmpName = "Asim Khan";
            Asim.EmpAge = 25;

            ViewData["Employee1"] = Asim;
            ViewBag.Employee2 = Asim;



            return View();
        }

        public ActionResult About()
        {
            return View();
        }
    }
}

Source Code Of Index.cshtml – View

@{
    ViewBag.Title = "Index";
}

<h2>Index</h2>

<h3>@ViewData["Message1"]</h3>
<h3>@ViewBag.Message2</h3>

<h3>@ViewData["CurrentDate1"]</h3>
<h3>@ViewBag.CurrentDate2</h3>

<ul>
    @{
        foreach (string i in (string[])ViewData["GamesArray1"])
        {
            <li>@i</li>
        }
    }
</ul>

<ul>
    @{
        foreach (string i in ViewBag.GamesArray2)
        {
            <li>@i</li>
        }
    }
</ul>

@{ 
    var a = (Difference_ViewBag_Viewdata.Models.Employee)ViewData["Employee1"];
    var b = ViewBag.Employee2;
}

@{ 
    <h3>@a.Empid</h3>
    <h3>@a.EmpName</h3>
    <h3>@a.EmpAge</h3>
}

@{ 
    <h3>@b.Empid</h3>
    <h3>@b.EmpName</h3>
    <h3>@b.EmpAge</h3>
}

Source Code Of About.cshtml – View

@{
    ViewBag.Title = "About";
}

<h2>About</h2>

<h3>ViewData data is = @ViewData["Message1"]</h3>
<h3>ViewBag data is = @ViewBag.Message2</h3>