Asp 1-mvc introduction
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The document provides an overview of ASP.NET MVC, including: - MVC separates an application into the model, view, and controller components. The model manages the data, the view displays the UI, and the controller handles input and logic. - ASP.NET MVC applies the MVC pattern to ASP.NET web applications. It uses conventions like controller and view file/folder names to associate controllers and views. - ASP.NET MVC has gone through multiple versions, adding features like the Razor view engine, Web API, and improvements to templates and validation. MVC controllers return action results like views to associate input with output.
![Mapping controller
• Controller selection based on URL
• Default URL routing
logic:/[Controller]/[ActionName]/[Parameters]
• Format for routing
inApp_Start/RouteConfig.cs](https://image.slidesharecdn.com/asp-1-mvcintroduction-210406043541/85/Asp-1-mvc-introduction-28-320.jpg)
Asp 1-mvc introduction
- 1. ASP.NET MVC
- 2. MVC • MVC separates the user interface of an application into three main aspects: – The Model – The View – The Controler
- 3. MVC • Model A set of classes that describes the data you’re working with as well as the business rules for how the data can be changed and manipulated • View Defines how the application’s UI will be displayed • Controller A set of classes that handles communication from the user, overall application flow, and application-specific logic.
- 4. MVC as Applied to Web Frameworks • Models: – Represent domain objects that encapsulate: • data stored in a database • code to manipulate the data • code to enforce domain-specific business logic • Example: encapsulating Entity Framework
- 5. MVC as Applied to Web Frameworks • View: – Template to dynamically generate HTML • Controller: – Class that manages the relationship between the View and the Model – It responds to user input, talks to the model, and decides which view to render (if any).
- 7. A Pattern • MVC is a pattern that can be applied to different frameworks • ASP.NET MVC – The MVC pattern has been applied to ASP.NET. This does not mean that it is the same as MVC running in other places.
- 8. ASP.NET MVC 3 • 10 months after MVC 2 – The Razor view engine – Support for .NET 4 Data Annotations – Improved model validation – Greater control and flexibility with support for dependency resolution and global action filters – Better JavaScript support with unobtrusive JavaScript, jQuery Validation, and JSON binding – Use of NuGet to deliver software and manage dependencies throughout the platform
- 9. Razor View Engine • Code-focused templating for HTML generation • Compact, expressive, and fluid • Not a new language • Easy to learn • Works with any text editor • IntelliSense • No XML-like heavy syntax
- 10. ASP.NET MVC 4 • Features include: – ASP.NET Web API – Enhancements to the default project templates – Mobile project template using jQuery Mobile – Display Modes – Task Support for Asynchronous Controllers – Bundling and Minification
- 11. ASP.NET Web API • Referred to as Web API • A framework that offers the ASP.NET MVC development style but is tailored to writing HTTP services. (service-oriented design) • Several MVC features have been adopted for HTTP Service domain: – Routing – Model Binding and Validation – Filters – Scaffolding – Easy Unit Testability
- 12. ASP.NET MVC 5 • http://www.asp.net/mvc/mvc5
- 13. Layout of an MVC project When you create a new MVC project, your solution should have the following structure in your Solution Explorer. 13
- 14. Layout of an MVC project 14
- 15. Layout of an MVC project 15 • App_Data –it’s meant to hold data for your application (just as the name says). A couple of examples would include a portable database (like SQL Server Compact Edition) or any kind of data files (XML, JSON, etc.). I prefer to use SQL Server. • App_Start – The App_Start folder contains the initialization and configuration of different features of your application. – BundleConfig.cs – This contains all of the configuration for minifying and compressing your JavaScript and CSS files into one file. – FilterConfig.cs – Registers Global Filters. – RouteConfig.cs – Configuration of your routes. There are other xxxxConfig.cs files that are added when you apply other MVC- related technologies (for example, WebAPI adds WebApiConfig.cs). • Content – This folder is meant for all of your static content like images and style sheets. It’s best to create folders for them like “images” or “styles” or “css”.
- 16. Layout of an MVC project 16 • Controllers – The controllers folder is where we place the controllers. • Models – This folder contains your business models. It’s better when you have these models in another project, but for demo purposes, we’ll place them in here. • Scripts – This is where your JavaScript scripts reside. • Views – This parent folder contains all of your HTML “Views” with each controller name as a folder. Each folder will contain a number of cshtml files relating to the methods in that folder’s controller. If we had a URL that looked like this: http://www.xyzcompany.com/Products/List we would have a Products folder with a List.cshtml file. We would also know to look in the Controllers folder and open the ProductsController.cs and look for the List method.
- 17. Layout of an MVC project 17 • Views/Shared – The Shared folder is meant for any shared cshtml files you need across the website. • Global.asax – The Global.asax is meant for the initialization of the web application. If you look inside the Global.asax, you’ll notice that this is where the RouteConfig.cs, BundleConfig.cs, and FilterConfig.cs are called when the application runs. • Web.Config – The web.config is where you place configuration settings for your application. For new MVC developers, it’s good to know that you can place settings inside the <appsettings> tag and place connection strings inside the <connectionstring> tag.
- 18. Controller • “Convention over configuration” • ASP.NET MVC is heavily convention-based – Uses Directory-naming structure when resolving view templates. • Allows you to omit the location path when referencing views from within a Controller class.
- 19. View • Each controller’s class name ends with Controller – LegalController, LegalServicesController, HomeController • One Views directory for all the views of your application • Views that controllers use live in a subdirectory of the Views main directory and are named according to the controller name(minus the Controller suffix) – Views for the LegalController would live in /Views/Legal • Reusable UI elements live in a similar structure, but in a Shared directory in the Views folder
- 20. Controller Basics • Model View Controller: – 1st Controller basics, then the other stuff. – Have a look at the HomeController • Responsible for deciding what will happen when you browse to the homepage of the website.
- 21. The Controller’s Role • Responsible for responding to user input, making changes to the model in response to user input if needed. • Controllers are concerned with the flow of the application, working with data that comes in and providing data going out to the relevant view.
- 22. The Controller’s Role • The URL tells the routing mechanism (later chapter) which controller class to instantiate and which action method to call, and supplies the required arguments to that method. • The controller’s method then decides which view to use, and that view then renders the HTML. • The controller’s method could return something other than a view.
- 23. The Controller’s Role • There is a relationship between the URL and the METHOD on a controller class. Not a relationship between the URL and a FILE on the web server. • MVC serves up the results of method calls, not dynamically generated pages. • (More about routing in later)
- 24. MVC Request processing pipeline
- 25. Modifying the LegalServicesController • The Browse and Details methods to cover additional scenarios.
- 26. Observation • Browsing to /LegalServices/Browse caused the browse method of the LegalServicesController to be executed. – NO extra configuration was needed. – This is routing in action. More later. • We returned text to the browser without a model or a view.
- 27. Oversimplified • The previous example was not common and was oversimplified. – You will almost always use Views – You will most often return ActionResult instead of strings – And routing is more complex that shown.
- 28. Mapping controller • Controller selection based on URL • Default URL routing logic:/[Controller]/[ActionName]/[Parameters] • Format for routing inApp_Start/RouteConfig.cs
- 29. URL routing • WebappURL without URL segments => HomeController::Index() • Index() –default method of a controller • /HelloWorld=> HelloWorldController • /HelloWorld/Index => HelloWorldController::Index() • http://webapp:port/HelloWorld/Welcome =>HelloWorldController::Welcome()
- 30. Parameters • /HelloWorld/Welcome?name=Scott&numtimes=4 • Introducing 2 parameters to Welcome method • Parameters passed as query strings!
- 32. Basic Controllers Summary • Controllers orchestrate the interactions of the user, the model objects and the views. • They are responsible for: – responding to the user input – Manipulating the appropriate model objects – And then selecting the appropriate view to display back to the user in response to the initial input
- 33. ActionResult • Before talking about Views, let’s look at ActionResults
- 35. The View • The user’s first impression of your site starts with the View • Responsible for providing the user interface to the user. • The view transforms a model into a format ready to be presented to the user. • The view examines the model object and transforms the contents to HTML
- 36. The View • Not all views render HTML, but HTML is the most common case • More info on alternate types of content later. • Views created using Razor view engine • Controller method returns View object • Controller method return type is ActionResult
- 37. Razor View Engine • What is Razor? – Introduced in ASP.NET MVC 3 and is the default view engine moving forward – Provides a clean, lightweight, simple view engine. – Provides a streamlined syntax for expressing views – Minimizes the amount of syntax and extra characters.
- 38. Example
- 39. Convention • The Views directory contains a folder for your controller, with the same name as the controller, but without the controller suffix. • HomeController has views in the Home directory • Within the view folder (also called controller folder) there’s a view file for each action method, named the same as the action method. • This is how views are associated to an action method. • An action method can return a ViewResult via the View() method.
- 40. View() Method • When the view name isn’t specified, the ViewResult returned by the action method applies a convention to locate the view. – It first looks for a view with the same name as the action within the /Views/ControllerName directory. “Ex: /views/home/Index.cshtml” • The View() method is overloaded. You can supply a view name to render a different view. “ex: View(“MyView”)” – It will still look in the same directory, but will look for the “MyView.cshtml” file. • View(“~/Views/DifferentDirectory/Index.cshtml”) – To get to a different directory, provide the full path to that directory. You must provide the file extension as well. This bypasses the internal lookup mechanism.