AdministratorWhat kind of object is ViewData?
ViewData is a ViewDataDictionary object accessed through string keys. String data can be stored and used directly without the need for a cast, but you must cast other ViewData object values to specific types when you extract them.
What is ViewData model in MVC?
In MVC, when we want to transfer the data from the controller to view, we use ViewData. It is a dictionary type that stores the data internally. ViewData contains key-value pairs which means each key must be a string in a dictionary. The only limitation of ViewData is, it can transfer data from controller to view.
Where ViewData is stored in MVC?
ViewBag and ViewData are part of state management. They are both objects that allow passing of data (mainly) from the Controller to the View. This happens entirely on the server side but the idea that the data is “stored” on the server is misleading.
How do I pass ViewData to view?
To pass the strongly-typed data from Controller to View using ViewData, we have to make a model class then populate its properties with some data and then pass that data to ViewData dictionary as Value and selecting Key’s name is the programmer’s choice.
Does ViewData use session?
In ASP.NET MVC there are three ways – ViewData, ViewBag and TempData to pass data from controller to view and in next request. Like WebForm, you can also use Session to persist data during a user session. Now question is that when to use ViewData, VieBag, TempData and Session. Each of them has its own importance.
What is ViewData and TempData?
ViewData is a dictionary object and it is property of ControllerBase class. ViewBag is Dynamic property of ControllerBase class. TempData is a dictionary object and it is property of controllerBase class.
What is difference between ViewData and TempData?
To summarize, ViewBag and ViewData are used to pass the data from Controller action to View and TempData is used to pass the data from action to another action or one Controller to another Controller.
What is the difference between View and ViewData is asp net?
ViewData and ViewBag are used for the same purpose — to transfer data from controller to view. ViewData is nothing but a dictionary of objects and it is accessible by string as key. ViewData is a property of controller that exposes an instance of the ViewDataDictionary class.
Can a model be assigned to Viewdata?
In this case, when the below Product Action is called a Model is created and assigned to ViewData for use in the View. This all works fine, the Model property is not-null, and the Views use of the Model property works.
Why does the view return a null reference when validation fails?
When the Product is updated and Post’ed back to the Controller all the data looks fine, but if the product fails validation and I return the View ActionResult (as shown below) the View encounters a null reference exception because the Views Model property is now null.
Can a model be assigned to a view in MVC 4?
I have a simple MVC 4 (Beta) Application and just observed something that I assume may be handled differently. In this case, when the below Product Action is called a Model is created and assigned to ViewData for use in the View. This all works fine, the Model property is not-null, and the Views use of the Model property works.
What is a null reference exception in Salesforce?
However, a null reference exception occurs if the Viewdata equals null. It happens inside the viewpage when it loops through the ViewData and displays products or reviews. The Null Reference Exception occurs when the following piece of code is reached: