Understanding ViewBag in ASP.NET Core MVC

In this article, we will explore how to use ViewBag in an ASP.NET Core 3.0 MVC application to pass data from a controller to a view. ViewBag is a dynamic object that provides a simple way to transfer temporary data without the need for strongly typed models.

What is ViewBag?

• ViewBag is a dynamic wrapper around ViewData, introduced in ASP.NET MVC.
• It allows you to pass data from a controller to a view.
• Being dynamic, it does not require typecasting for complex types.
• However, its scope is limited to the current request, so the data cannot be retained across redirects or multiple requests.

When to Use ViewBag

Use ViewBag when:

• You need to pass simple, one-time data (like a message, title, or user info).
• You do not require strong typing.
• You want a quick and dynamic way to transfer data between the controller and the view.

Avoid using ViewBag for large or complex data models. Use ViewModel or ViewData in such cases.

Step-by-Step Example

Step 1: Create a Controller

We are going add Controller with Name Demo3 with Index action method inside that we are going to declare ViewBag with a string value.

using Microsoft.AspNetCore.Mvc;

namespace WebApplication2.Controllers
{
    public class Demo3Controller : Controller
    {
        public IActionResult Index()
        {
            ViewBag.Message = "Hi Message";
            return View();
        }
    }
}

Step 2: Create a View

<h1>Index</h1>

Message:- @ViewBag.Message

Read more :- https://tutexchange.com/quick-view-at-developer-features-of-bugpoint-application/

Read more:- https://learn.microsoft.com/en-us/answers/questions/796983/viewbag-in-asp-net-core