Passing data: ViewData, ViewBag, TempData, strongly typed models — ASP.NET Core MVC (and Razor Pages)

7. Passing data: ViewData, ViewBag, TempData, strongly typed models

Intermediate★ Must knowLesson 7 of 15

	Type	Lifetime	Use
Strongly typed `@model`	Any class	Current request	Preferred — compile-time checked
`ViewData`	`ViewDataDictionary` (string keys)	Current request	Small extras, e.g. page title
`ViewBag`	`dynamic` wrapper over ViewData	Current request	Same as ViewData, no casting
`TempData`	Dictionary backed by cookie (default) or session	Until read (survives one redirect)	Flash messages after PRG
Session	`ISession` (needs `AddSession` + distributed cache)	Across requests	Wizard state, cart (prefer DB for important data)

csharp

ViewData["Title"] = "Products";
ViewBag.Count = 5;
TempData["Message"] = "Saved";           // read once on next request; TempData.Keep() / Peek() to retain

cshtml

@model IEnumerable<Product>
<h1>@ViewData["Title"]</h1>
@if (TempData["Message"] is string msg) { <div class="alert alert-success">@msg</div> }