Asp.Net MVC Exploring Controllers in-depth Part 2.Best Dot Net Courses

Learn MVC to build web apps using the Model View Controller pattern. ASP.NET MVC 5 provides this functionality to the ASP.NET framework as an alternative to the Web Forms pattern

Passing data from Controller to View

ViewBag vs. ViewData vs. TempData

All three are properties

- ViewData is a dictionary object that you put data into, which then becomes available to the ViewData is a derivative of the ViewDataDictionary class, so you can access by the familiar “key/value” syntax.
- ViewBag object is a wrapper around the ViewData object that allows you to create dynamic properties for the ViewBag.
- Both the ViewData and ViewBag objects are great for accessing extra data (i.e., outside the data model), between the controller
- Asp.Net MVC Exploring Controllers in-depth Part 2.Best Dot Net Courses

TempData has an additional advantage of Passing data between the current and next HTTP requests.

public ViewResult Index()
{
int hour = DateTime.Now.Hour;
ViewData["Greetings"] = (hour < 12 ? "Good Morning" : "Good Afternoon"); 
ViewBag.Greetings = (hour < 12 ? "Good Morning" : "Good Afternoon"); 
TempData["Greetings"] = (hour < 12 ? "Good Morning" : "Good Afternoon"); 
return View();
}

public ViewResult Index()

{

int hour = DateTime.Now.Hour;

ViewData["Greetings"] = (hour < 12 ? "Good Morning" : "Good Afternoon");

ViewBag.Greetings = (hour < 12 ? "Good Morning" : "Good Afternoon");

TempData["Greetings"] = (hour < 12 ? "Good Morning" : "Good Afternoon");

return View();

}

Update your Index.aspx view template to display it as follows:

<body>
@ViewData["Greetings"], Deccansoft (from the view)! 
@ViewBag.Greetings, Deccansoft (from the view)! 
@TempData["Greetings"], Deccansoft (from the view)! 
@Html.ActionLink("Postback For TempData", "TempDataDemoView")
</body>

<body>

@ViewData["Greetings"], Deccansoft (from the view)!

@ViewBag.Greetings, Deccansoft (from the view)!

@TempData["Greetings"], Deccansoft (from the view)!

@Html.ActionLink("Postback For TempData", "TempDataDemoView")

</body>

public ViewResult TempDataDemoView()
{
var vd = ViewData["Greetings"]; 
var vb = ViewBag.Greetings;
var td = TempData["Greetings"]; 
return View();
}
Put a break point and observe that vd, vb are null but td is not.

public ViewResult TempDataDemoView()

{

var vd = ViewData["Greetings"];

var vb = ViewBag.Greetings;

var td = TempData["Greetings"];

return View();

}

Put a break point and observe that vd, vb are null but td is not.

TempData.Keep(); – To retain key in TempData in subsequent round trip

Note: TempData uses HttpSession and can be demonstrated by disabling session in web.config

If you are interested in developing dynamic websites and web applications using ASP.NET Framework, learning ASP.NET Web Forms from BestDotNetTraining’s online training would be of great use. And C# is the best choice of a programming language used for writing code in ASP.NET websites.

Web Forms is one of the 3 programming models for creating ASP.NET websites and web applications. The other two programming models are Web Pages and MVC (Model, View, and Controller).

Asp.Net MVC Exploring Controllers in depth Part 2.Best Dot Net Courses — Asp.Net MVC Exploring Controllers in-depth Part 2.Best Dot Net Courses

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