Working in Asp.Net MVC 3.0 in comparison to Web Forms

Working in Asp.Net MVC 3.0 in comparison to Web Forms

http://kb.vteamslabs.com 1

By: Shahid Maqsood

Session Agenda• Overview of previous session• Working of Controller, Model, View Model and Views• Brief Introduction to Entity Framework.• How following functionalities of Asp.Net are

used/implemented in MVC environment.– Master Page – Web Controls – Validation Controls – User Controls– Events Handling– State Management

2http://kb.vteamslabs.com

Controller

• With traditional web frameworks, incoming URLs are typically mapped to files on disk. – For example: "/Products.aspx" or "/Products.php“

• Web-based MVC frameworks map URLs to server code in a slightly different way. Instead of mapping incoming URLs to files, they map URLs to methods on classes. – Classes are called “Controllers” and its Methods are

called “Action Methods”.


Controllers Responsibilities

• Controllers are responsible for– Locating the appropriate action method to call and

validating that it can be called– Getting the values to use as the action method's

arguments– Handling all errors that might occur during the

execution of the action method– Determining the Response to send back to the client

(display HTML, download a file, redirect to a different URL, etc.)

– Providing the default WebFormViewEngine


http://msdn.microsoft.com/en-us/library/system.web.mvc.webformviewengine.aspx

Events Handling (Action Method)

• The controller defines action methods. – Action methods typically have a one-to-one

mapping with user interactions– Action methods return the ActionResult return type– There are two type of action behavior of Action

methods GET and POST. GET is the default behavior.


ActionResult Return TypeAction Result Helper Method Description

ViewResult View Renders a view as a Web page.

PartialViewResult PartialView Renders a partial view, which defines a section of a view that can be rendered inside another view.

RedirectResult Redirect Redirects to another action method by using its URL.

ContentResult Content Returns a user-defined content type.

JsonResult Json Returns a serialized JSON object.

JavaScriptResult JavaScript Returns a script that can be executed on the client.

FileResult File Returns binary output to write to the response.

EmptyResult (None)Represents a return value that is used if the action method must return a null result (void).


http://msdn.microsoft.com/en-us/library/system.web.mvc.viewresult.aspx

http://msdn.microsoft.com/en-us/library/system.web.mvc.controller.view.aspx

http://msdn.microsoft.com/en-us/library/system.web.mvc.partialviewresult.aspx

http://msdn.microsoft.com/en-us/library/system.web.mvc.controller.partialview.aspx

http://msdn.microsoft.com/en-us/library/system.web.mvc.redirectresult.aspx

http://msdn.microsoft.com/en-us/library/system.web.mvc.controller.redirect.aspx

http://msdn.microsoft.com/en-us/library/system.web.mvc.contentresult.aspx

http://msdn.microsoft.com/en-us/library/system.web.mvc.controller.content.aspx

http://msdn.microsoft.com/en-us/library/system.web.mvc.jsonresult.aspx

http://msdn.microsoft.com/en-us/library/system.web.mvc.controller.json.aspx

http://msdn.microsoft.com/en-us/library/system.web.mvc.javascriptresult.aspx

http://msdn.microsoft.com/en-us/library/system.web.mvc.controller.javascript.aspx

http://msdn.microsoft.com/en-us/library/system.web.mvc.fileresult.aspx

http://msdn.microsoft.com/en-us/library/system.web.mvc.controller.file.aspx

http://msdn.microsoft.com/en-us/library/system.web.mvc.emptyresult.aspx

Model

• Models hold and manipulate data.• They are usually database entities which are

mapped on table fields.


Entity Framework

• Entity Framework (EF) support is included in ASP.NET MVC 3 projects to query and update the database.

• EF is a flexible object relational mapping (ORM) data API that enables developers to query and update data stored in a database in an object-oriented way.

• It has two approaches I-e Model First and Code First.


Entity Framework

• In Model-first approach, you run a wizard and select the tables for which you need to create entities. It will create all the classes for you.

• In Code-first approach, you create model objects b writing simple classes. And then it allows you to create your database on the fly from your classes.


Views

• Views hold our UI templates• ViewEngine is used to render the contents• ViewBag is used to pass data from Controllers

to Views• ViewModel (@model) is used for strongly-

typed views.• Layout is used for common site elements


Add View

• View name• View engine• Strongly typed view• Partial view• Layout or master

page


View Engine

• Following are the major View Engines– Razor View Engine– ASPX View Engine– Spark View Engine– Nhaml View Engine– Custom View Engine (WebFormViewEngine)


ViewModels

• ViewModels are strongly typed classes which are optimized for our specific view scenarios.

• For example, Sometimes we need to use more properties for managing the view but our domain model doesn’t allow them because they are mapped to database tables only. So, we employ a view model for this kind of scenarios.


Master Page (Layout)

• Using a Layout for common site elements– Most websites have

content which is shared between many pages: navigation, footers, logo images, stylesheet references, etc.

– The Razor view engine makes this easy to manage using a page called _Layout.cshtml


_Layout.cshtml File


Web Controls (Html Helpers)

• In Web Forms, we have web controls in System.Web.UI I-e Textbox, Dropdownlist, Label, Checkbox, Radiobutton etc.

• In MVC, above controls are not available. MVC View Engine provides Html helpers for these controls.

• Eamples:• @Html.EditorFor(model => model.Title)

@Html.DropDownList("ArtistId", String.Empty)@Html.LabelFor(model => model.Price)


Validation Controls (Data Annotations)

• In Web forms, we have validation controls to perform validations I-e RequiredFieldValidator, RegularExpressionValidator etc

• In MVC, we specify validation in model classes along with properties through Data Annotations. And then we use Html Helpers to specify the place of validation messages next to controls.

• Example:@Html.EditorFor(model => model.Title) @Html.ValidationMessageFor(model => model.Title)


Data Annotations


Web User Controls (Partial Views)

• In Web forms, we have Web User Controls for managing the repeating functionality which can be used on multiple pages.

• In MVC, the alternative is to use Partial Views. The Partial Views can be called inside the views or the layout (Master Page) views.

• Example:@Html.Partial("_LogOnPartial")

• Partial Views are added to Shared folder.


State Management

• Should not use View State.• No Control View State.• ViewBag to communicate between Controller

and View• Sessions are available.


Further readings

• www.asp.net/mvc• http://

www.asp.net/mvc/tutorials/mvc-music-store • http://msdn.microsoft.com/en-us/library/dd3816

19.aspx• http://msdn.microsoft.com/en-us/library/dd3816

12.aspx


http://www.asp.net/mvc

http://www.asp.net/mvc/tutorials/mvc-music-store



http://msdn.microsoft.com/en-us/library/dd381619.aspx




Thank you!

Questions please?


Working in Asp.Net MVC 3.0 in comparison to Web Forms

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