--- title: Add a view to an ASP.NET Core MVC app author: rick-anderson description: Adding a view to a simple ASP.NET Core MVC app ms.author: riande ms.date: 03/04/2017 uid: tutorials/first-mvc-app/adding-view --- # Add a view to an ASP.NET Core MVC app By [Rick Anderson](https://twitter.com/RickAndMSFT) In this section you modify the `HelloWorldController` class to use [Razor](xref:mvc/views/razor) view files to cleanly encapsulate the process of generating HTML responses to a client. You create a view template file using Razor. Razor-based view templates have a *.cshtml* file extension. They provide an elegant way to create HTML output with C#. Currently the `Index` method returns a string with a message that's hard-coded in the controller class. In the `HelloWorldController` class, replace the `Index` method with the following code: [!code-csharp[](~/tutorials/first-mvc-app/start-mvc/sample/MvcMovie/Controllers/HelloWorldController.cs?name=snippet_4)] The preceding code calls the controller's method. It uses a view template to generate an HTML response. Controller methods (also known as *action methods*), such as the `Index` method above, generally return an (or a class derived from ), not a type like `string`. ## Add a view # [Visual Studio](#tab/visual-studio) * Right click on the *Views* folder, and then **Add > New Folder** and name the folder *HelloWorld*. * Right click on the *Views/HelloWorld* folder, and then **Add > New Item**. * In the **Add New Item - MvcMovie** dialog * In the search box in the upper-right, enter *view* * Select **Razor View** * Keep the **Name** box value, *Index.cshtml*. * Select **Add** ![Add New Item dialog](adding-view/_static/add_view.png) # [Visual Studio Code](#tab/visual-studio-code) Add an `Index` view for the `HelloWorldController`. * Add a new folder named *Views/HelloWorld*. * Add a new file to the *Views/HelloWorld* folder name *Index.cshtml*. # [Visual Studio for Mac](#tab/visual-studio-mac) * Right click on the *Views* folder, and then **Add > New Folder** and name the folder *HelloWorld*. * Right click on the *Views/HelloWorld* folder, and then **Add > New File**. * In the **New File** dialog: * Select **Web** in the left pane. * Select **Empty HTML file** in the center pane. * Type *Index.cshtml* in the **Name** box. * Select **New**. ![Add New Item dialog](adding-view/_static/add_view.png) --- Replace the contents of the *Views/HelloWorld/Index.cshtml* Razor view file with the following: [!code-HTML[](~/tutorials/first-mvc-app/start-mvc/sample/MvcMovie22/Views/HelloWorld/Index1.cshtml?highlight=7)] Navigate to `https://localhost:xxxx/HelloWorld`. The `Index` method in the `HelloWorldController` didn't do much; it ran the statement `return View();`, which specified that the method should use a view template file to render a response to the browser. Because you didn't explicitly specify the name of the view template file, MVC defaulted to using the *Index.cshtml* view file in the */Views/HelloWorld* folder. The image below shows the string "Hello from our View Template!" hard-coded in the view. ![Browser window](~/tutorials/first-mvc-app/adding-view/_static/hell_template.png) ## Change views and layout pages Select the menu links (**MvcMovie**, **Home**, and **Privacy**). Each page shows the same menu layout. The menu layout is implemented in the *Views/Shared/_Layout.cshtml* file. Open the *Views/Shared/_Layout.cshtml* file. [Layout](xref:mvc/views/layout) templates allow you to specify the HTML container layout of your site in one place and then apply it across multiple pages in your site. Find the `@RenderBody()` line. `RenderBody` is a placeholder where all the view-specific pages you create show up, *wrapped* in the layout page. For example, if you select the **Privacy** link, the **Views/Home/Privacy.cshtml** view is rendered inside the `RenderBody` method. ## Change the title, footer, and menu link in the layout file * In the title and footer elements, change `MvcMovie` to `Movie App`. * Change the anchor element `MvcMovie` to `Movie App`. The following markup shows the highlighted changes: [!code-html[](~/tutorials/first-mvc-app/start-mvc/sample/MvcMovie22/Views/Shared/_Layout.cshtml?highlight=6,24,51)] In the preceding markup, the `asp-area` [anchor Tag Helper attribute](xref:mvc/views/tag-helpers/builtin-th/anchor-tag-helper) was omitted because this app is not using [Areas](xref:mvc/controllers/areas). **Note**: The `Movies` controller has not been implemented. At this point, the `Movie App` link is not functional. Save your changes and select the **Privacy** link. Notice how the title on the browser tab displays **Privacy Policy - Movie App** instead of **Privacy Policy - Mvc Movie**: ![Privacy tab](~/tutorials/first-mvc-app/adding-view/_static/about2.png) Select the **Home** link and notice that the title and anchor text also display **Movie App**. We were able to make the change once in the layout template and have all pages on the site reflect the new link text and new title. Examine the *Views/_ViewStart.cshtml* file: ```HTML @{ Layout = "_Layout"; } ``` The *Views/_ViewStart.cshtml* file brings in the *Views/Shared/_Layout.cshtml* file to each view. The `Layout` property can be used to set a different layout view, or set it to `null` so no layout file will be used. Change the title and `

` element of the *Views/HelloWorld/Index.cshtml* view file: [!code-HTML[](~/tutorials/first-mvc-app/start-mvc/sample/MvcMovie/Views/HelloWorld/Index2.cshtml?highlight=2,5)] The title and `

` element are slightly different so you can see which bit of code changes the display. `ViewData["Title"] = "Movie List";` in the code above sets the `Title` property of the `ViewData` dictionary to "Movie List". The `Title` property is used in the `` HTML element in the layout page: ```HTML <title>@ViewData["Title"] - Movie App ``` Save the change and navigate to `https://localhost:xxxx/HelloWorld`. Notice that the browser title, the primary heading, and the secondary headings have changed. (If you don't see changes in the browser, you might be viewing cached content. Press Ctrl+F5 in your browser to force the response from the server to be loaded.) The browser title is created with `ViewData["Title"]` we set in the *Index.cshtml* view template and the additional "- Movie App" added in the layout file. Also notice how the content in the *Index.cshtml* view template was merged with the *Views/Shared/_Layout.cshtml* view template and a single HTML response was sent to the browser. Layout templates make it really easy to make changes that apply across all of the pages in your application. To learn more see [Layout](xref:mvc/views/layout). ![Movie List view](~/tutorials/first-mvc-app/adding-view/_static/hell3.png) Our little bit of "data" (in this case the "Hello from our View Template!" message) is hard-coded, though. The MVC application has a "V" (view) and you've got a "C" (controller), but no "M" (model) yet. ## Passing Data from the Controller to the View Controller actions are invoked in response to an incoming URL request. A controller class is where the code is written that handles the incoming browser requests. The controller retrieves data from a data source and decides what type of response to send back to the browser. View templates can be used from a controller to generate and format an HTML response to the browser. Controllers are responsible for providing the data required in order for a view template to render a response. A best practice: View templates should **not** perform business logic or interact with a database directly. Rather, a view template should work only with the data that's provided to it by the controller. Maintaining this "separation of concerns" helps keep the code clean, testable, and maintainable. Currently, the `Welcome` method in the `HelloWorldController` class takes a `name` and a `ID` parameter and then outputs the values directly to the browser. Rather than have the controller render this response as a string, change the controller to use a view template instead. The view template generates a dynamic response, which means that appropriate bits of data must be passed from the controller to the view in order to generate the response. Do this by having the controller put the dynamic data (parameters) that the view template needs in a `ViewData` dictionary that the view template can then access. In *HelloWorldController.cs*, change the `Welcome` method to add a `Message` and `NumTimes` value to the `ViewData` dictionary. The `ViewData` dictionary is a dynamic object, which means any type can be used; the `ViewData` object has no defined properties until you put something inside it. The [MVC model binding system](xref:mvc/models/model-binding) automatically maps the named parameters (`name` and `numTimes`) from the query string in the address bar to parameters in your method. The complete *HelloWorldController.cs* file looks like this: [!code-csharp[](~/tutorials/first-mvc-app/start-mvc/sample/MvcMovie/Controllers/HelloWorldController.cs?name=snippet_5)] The `ViewData` dictionary object contains data that will be passed to the view. Create a Welcome view template named *Views/HelloWorld/Welcome.cshtml*. You'll create a loop in the *Welcome.cshtml* view template that displays "Hello" `NumTimes`. Replace the contents of *Views/HelloWorld/Welcome.cshtml* with the following: [!code-html[](~/tutorials/first-mvc-app/start-mvc/sample/MvcMovie/Views/HelloWorld/Welcome.cshtml)] Save your changes and browse to the following URL: `https://localhost:xxxx/HelloWorld/Welcome?name=Rick&numtimes=4` Data is taken from the URL and passed to the controller using the [MVC model binder](xref:mvc/models/model-binding) . The controller packages the data into a `ViewData` dictionary and passes that object to the view. The view then renders the data as HTML to the browser. ![Privacy view showing a Welcome label and the phrase Hello Rick shown four times](~/tutorials/first-mvc-app/adding-view/_static/rick2.png) In the sample above, the `ViewData` dictionary was used to pass data from the controller to a view. Later in the tutorial, a view model is used to pass data from a controller to a view. The view model approach to passing data is generally much preferred over the `ViewData` dictionary approach. See [When to use ViewBag, ViewData, or TempData](http://www.rachelappel.com/when-to-use-viewbag-viewdata-or-tempdata-in-asp-net-mvc-3-applications/) for more information. In the next tutorial, a database of movies is created. > [!div class="step-by-step"] > [Previous](adding-controller.md) > [Next](adding-model.md)