What is ViewData in MVC

Question

What is ViewData in MVC?

Nilesh Jadav · Answer

hey ! ASP.NET MVC offers us three options - ViewData ViewBag and TempData for passing data from controller to view and in next request. ViewData and ViewBag are almost similar and TempData performs additional responsibility. ViewData and ViewBag are used for the same purpose to transfer data from controller to view. Both life lies only in current request. ViewData is nothing but dictionary of object and it is accessible by string as key. ViewData is property of controller that exposes an instance of the ViewDataDictionary class. ViewBag is very similar to ViewData. ViewBag is a dynamic property (dynamic keyword which is introduced in .net framework 4.0). ViewBag is able to set and get value dynamically and able to add any number of additional fields without converts it to strongly typed. ViewBag is just a wrapper around the ViewData. In Asp.Net MVC there are three ways to pass/store data between the controllers and views. ViewData ViewData is used to pass data from controller to view It is derived from ViewDataDictionary class It is available for the current request only Requires typecasting for complex data type and checks for null values to avoid error If redirection occurs then its value becomes null ViewBag ViewBag is also used to pass data from the controller to the respective view ViewBag is a dynamic property that takes advantage of the new dynamic features in C# 4.0 It is also available for the current request only If redirection occurs then its value becomes null Doesn’t require typecasting for complex data type TempData TempData is derived from TempDataDictionary class TempData is used to pass data from the current request to the next request It keeps the information for the time of an HTTP Request. This means only from one page to another. It helps to maintain the data when we move from one controller to another controller or from one action to another action It requires typecasting for complex data type and checks for null values to avoid error. Generally it is used to store only one time messages like the error messages and validation messages Check this link : http://www.c-sharpcorner.com/Blogs/12427/viewdata-vs-viewbag-vs-tempdata-in-mvc.aspx If you satisfy with the answer Please accept it. Thank you !

Ravi Patel · Answer

Hi Gaurav ViewData is used for passing data from controller to view. public ActionResult Index() { ViewData[ Message  ] =  Hi Welcome to MVC  ; return View(); } and in View page ViewData[ Message  ]

Priyaranjan K S · Answer

Hi Gaurav ViewData allows the developers to pass data from controllers to views. The Controller base class has a ViewData dictionary property that can be used to populate data that you want to pass to a View. You add objects into the ViewData dictionary using a key/value pattern.This then becomes accessible in the View . Code base representation and control flow is as below : You may refer these links for more information : https://www.youtube.com/watch?v=KrdMO2akohE http://www.c-sharpcorner.com/UploadFile/abhikumarvatsa/various-ways-to-pass-data-from-controller-to-view-in-mvc/ Thanks Priyan If you found this useful Please mark this as Answer

Sujeet Suman · Answer

=> ViewData is a dictionary object that is derived from ViewDataDictionary class. Example: - public ViewDataDictionary ViewData { get; set; } => ViewData is a property of ControllerBase class. => ViewData is used to pass data from controller to corresponding view. => It’s life lies only during the current request. => If redirection occurs then it’s value becomes null. => It’s required typecasting for getting data and check for null values to avoid error. Gaurav for more details please once go through below link: http://www.dotnet-tricks.com/Tutorial/mvc/9KHW190712-ViewData-vs-ViewBag-vs-TempData-vs-Session.html If this is helpful for you then please accept my Answer .