| Developer(s) | Microsoft |
|---|---|
| Initial release | January 2002 |
| Stable release | 4.5 / 15 August 2012 |
| Written in | .NET languages |
| Operating system | Microsoft Windows |
| Type | Web application framework |
| License | Proprietary |
| Website | www.asp.net |
| Filename extension | .aspx |
|---|---|
| Internet media type | text/html |
| Developed by | Microsoft |
ASP.NET is a server-side Web application framework designed for Web development to produce dynamic Web pages. It was developed by Microsoft to allow programmers to build dynamic web sites, web applications and web services. It was first released in January 2002 with version 1.0 of the .NET Framework, and is the successor to Microsoft's Active Server Pages (ASP) technology. ASP.NET is built on the Common Language Runtime (CLR), allowing programmers to write ASP.NET code using any supported .NET language. The ASP.NET SOAP extension framework allows ASP.NET components to process SOAP messages.
After four years of development, and a series of beta releases in 2000 and 2001, ASP.NET 1.0 was released on January 5, 2002 as part of version 1.0 of the .NET Framework. Even prior to the release, dozens of books had been written about ASP.NET, and Microsoft promoted it heavily as part of its platform for Web services. Scott Guthrie became the product unit manager for ASP.NET, and development continued apace, with version 1.1 being released on April 24, 2003 as a part of Windows Server 2003. This release focused on improving ASP.NET's support for mobile devices.
ASP.NET Web pages, known officially as Web Forms, are the main building blocks for application development. Web forms are contained in files with a ".aspx" extension; these files typically contain static (X)HTML markup, as well as markup defining server-side Web Controls and User Controls where the developers place all the rc content[further explanation needed] for the Web page. Additionally, dynamic code which runs on the server can be placed in a page within a block <% -- dynamic code -- %>, which is similar to other Web development technologies such as PHP, JSP, and ASP. With ASP.NET Framework 2.0, Microsoft introduced a new code-behind model which allows static text to remain on the .aspx page, while dynamic code remains in an .aspx.vb or .aspx.cs or .aspx.fs file (depending on the programming language used).
A directive is special instructions on how ASP.NET should process the page. The most common directive is <%@ Page %> which can specify many attributes used by the ASP.NET page parser and compiler.
<%@ Page Language="C#" %> <!DOCTYPE html PUBLIC "---//W3C//DTD XHTML 1.0 //EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <script runat="server"> protected void Page_Load(object sender, EventArgs e) { // Assign the datetime to label control lbl1.Text = DateTime.Now.ToLongTimeString(); lbl.Text = Ahmad(); lbl1.Text = DateTime.Now.ToShortTimeString(); } </script> <html xmlns="http://www.w3.org/1999/xhtml"> <head runat="server"> <title>Sample page</title> </head> <body> <form id="form1" runat="server">
<%@ Page Language="C#" CodeFile="SampleCodeBehind.aspx.cs" Inherits="Website.SampleCodeBehind" AutoEventWireup="true" %>
The above tag is placed at the beginning of the ASPX file. The CodeFile property of the @ Page directive specifies the file (.cs or .vb or .fs) acting as the code-behind while the Inherits property specifies the Class from which the Page is derived. In this example, the @ Page directive is included in SampleCodeBehind.aspx, then SampleCodeBehind.aspx.cs acts as the code-behind for this page:
Source language C#:
using System; namespace Website { public partial class SampleCodeBehind : System.Web.UI.Page { protected void Page_Load(object sender, EventArgs e) { Response.Write("Hello, world"); } } }
Source language Visual Basic.NET:
Imports System Namespace Website Public Partial Class SampleCodeBehind Inherits System.Web.UI.Page Protected Sub Page_Load(ByVal sender As Object, ByVal e As EventArgs) Response.Write("Hello, world") End Sub End Class End Namespace
In this case, the Page_Load() method is called every time the ASPX page is requested. The programmer can implement event handlers at several stages of the page execution process to perform processing.
User controls are encapsulations of sections of pages which are registered and used as controls in ASP.NET.etc.
Programmers can also build custom controls for ASP.NET applications. Unlike user controls, these controls do not have an ASCX markup file, having all their code compiled into a dynamic link library (DLL) file. Such custom controls can be used across multiple Web applications and Visual Studio projects.
ASP.NET uses a visited composites rendering technique. During compilation, the template (.aspx) file is compiled into initialization code which builds a control tree (the composite) representing the original template. Literal text goes into instances of the Literal control class, and server controls are represented by instances of a specific control class. The initialization code is combined with user-written code (usually by the assembly of multiple partial classes) and results in a class specific for the page. The page doubles as the root of the control tree.
Actual requests for the page are processed through a number of steps. First, during the initialization steps, an instance of the page class is created and the initialization code is executed. This produces the initial control tree which is now typically manipulated by the methods of the page in the following steps. As each node in the tree is a control represented as an instance of a class, the code may change the tree structure as well as manipulate the properties/methods of the individual nodes. Finally, during the rendering step a visitor is used to visit every node in the tree, asking each node to render itself using the methods of the visitor. The resulting HTML output is sent to the client.
After the request has been processed, the instance of the page class is discarded and with it the entire control tree. This is a source of confusion among novice ASP.NET programmers who rely on the class instance members that are lost with every page request/response cycle.
ASP.NET applications are hosted by a Web server and are accessed using the stateless HTTP protocol. As such, if an application uses stateful interaction, it has to implement state management on its own. ASP.NET provides various functions for state management. Conceptually, Microsoft treats "state" as GUI state. Problems may arise if an application needs to keep track of "data state"; for example, a finite-state machine which may be in a transient state between requests (lazy evaluation) or which takes a long time to initialize. State management in ASP.NET pages with authentication can make Web scraping difficult or impossible.
Application state is held by a collection of shared user-defined variables. These are set and initialized when the Application_OnStart event fires on the loading of the first instance of the application and are available until the last instance exits. Application state variables are accessed using the Applications collection, which provides a wrapper for the application state. Application state variables are identified by name.
Server-side Session state is held by a collection of user-defined session variables that are persistent during a user session. These variables, accessed using the Session collection, are unique to each session instance. The variables can be set to be automatically destroyed after a defined time of inactivity even if the session does not end. Client-side user session is maintained by either a cookie or by encoding the session ID in the URL itself.
ASP.NET supports three modes of persistence for server-side session variables:
ASP.NET session state enables you to store and retrieve values for a user as the user navigates ASP.NET pages in a Web application. HTTP is a stateless protocol. This means that a Web server treats each HTTP request for a page as an independent request. The server retains no knowledge of variable values that were used during previous requests. ASP.NET session state identifies requests from the same browser during a limited time window as a session, and provides a way to persist variable values for the duration of that session. By default, ASP.NET session state is enabled for all ASP.NET applications.
Alternatives to session state include the following:
For a comparison of different state-management options, see ASP.NET State Management Recommendations. Session
View state refers to the page-level state management mechanism, utilized by the HTML pages emitted by ASP.NET applications to maintain the state of the Web form controls and widgets. The state of the controls is encoded and sent to the server at every form submission in a hidden field known as __VIEWSTATE. The server sends back the variable so that when the page is re-rendered, the controls render at their last state. At the server side, the application may change the viewstate, if the processing requires a change of state of any control. The states of individual controls are decoded at the server, and are available for use in ASP.NET pages using the ViewState collection.
The main use for this is to preserve form information across postbacks. View state is turned on by default and normally serializes the data in every control on the page regardless of whether it is actually used during a postback. This behavior can (and should) be modified, however, as View state can be disabled on a per-control, per-page, or server-wide basis.
Developers need to be wary of storing sensitive or private information in the View state of a page or control, as the base64 string containing the view state data can easily be de-serialized. By default, View state does not encrypt the __VIEWSTATE value. Encryption can be enabled on a server-wide (and server-specific) basis, allowing for a certain level of security to be maintained.
ASP.NET offers a "Cache" object that is shared across the application and can also be used to store various objects. The "Cache" object holds the data only for a specified amount of time and is automatically cleaned after the session time-limit elapses.
Other means of state management that are supported by ASP.NET are cookies, caching, and using the query string.
When first released, ASP.NET lacked a template engine. Because the .NET Framework is object-oriented and allows for inheritance, many developers would define a new base class that inherits from "System.Web.UI.Page", write methods there that render HTML, and then make the pages in their application inherit from this new class. While this allows for common elements to be reused across a site, it adds complexity and mixes source code with markup. Furthermore, this method can only be visually tested by running the application – not while designing it. Other developers have used include files and other tricks to avoid having to implement the same navigation and other elements in every page.
ASP.NET 2.0 introduced the concept of "master pages", which allow for template-based page development. A Web application can have one or more master pages, which, beginning with ASP.NET 2.0, can be nested. Master templates have place-holder controls, called ContentPlaceHolders to denote where the dynamic content goes, as well as HTML and JavaScript shared across child pages.
Child pages use those ContentPlaceHolder controls, which must be mapped to the place-holder of the master page that the content page is populating. The rest of the page is defined by the shared parts of the master page, much like a mail merge in a word processor. All markup and server controls in the content page must be placed within the ContentPlaceHolder control.
When a request is made for a content page, ASP.NET merges the output of the content page with the output of the master page, and sends the output to the user.
The master page remains fully accessible to the content page. This means that the content page may still manipulate headers, change title, configure caching etc. If the master page exposes public properties or methods (e.g. for setting copyright notices) the content page can use these as well.
Other file extensions associated with different versions of ASP.NET include:
| Extension | Introduced in version | Description |
|---|---|---|
| asax | 1.0 | This is the global application file.You can use this file to define global variable(Variable that can be accessed from any Web page in the Web application.) It is mostly used to define the overall application event related to application & session object.Global.asax, used for application-level logic |
| ascx | 1.0 | User Control, used for User Control files logic |
| ashx | 1.0 | custom HTTP handlers Do not have a user interface. |
| asmx | 1.0 | Web service pages. From version 2.0 a Code behind page of an asmx file is placed into the app_code folder. |
| aspx | 1.0 | An ASP.NET Web Forms page that can contain Web controls and presentation and business logic. http://msdn.microsoft.com/en-us/library/2wawkw1c.aspx |
| axd | 1.0 | when enabled in web.config requesting trace.axd outputs application-level tracing. Also used for the special webresource.axd handler which allows control/component developers to package a component/control complete with images, script, css etc. for deployment in one file (an 'assembly') |
| browser | 2.0 | browser capabilities files stored in XML format; introduced in version 2.0. ASP.NET 2 includes many of these by default, to support common Web browsers. These specify which browsers have which abilities, so that ASP.NET 2 can automatically customize and optimize its output accordingly. Special .browser files are available for free download to handle, for instance, the W3C Validator, so that it properly shows standards-compliant pages as being standards-compliant. Replaces the harder-to-use BrowserCaps section that was in machine.config and could be overridden in web.config in ASP.NET 1.x. |
| config | 1.0 | web.config is the only file in a specific Web application to use this extension by default (machine.config similarly affects the entire Web server and all applications on it), however ASP.NET provides facilities to create and consume other config files. These are stored in XML format. |
| cs/vb | 1.0 | Code files (cs indicates C#, vb indicates Visual Basic, fs indicates F#). Code behind files (see above) predominantly have the extension ".aspx.cs" or ".aspx.vb" for the two most common languages. Other code files (often containing common "library" classes) can also exist in the Web folders with the cs/vb extension. In ASP.NET 2 these should be placed inside the App_Code folder where they are dynamically compiled and available to the whole application. |
| cshtml | 4.1 | Views (mixed C# and HTML using Razor syntax) |
| dbml | 3.5 | LINQ to SQL data classes file |
| edmx | 3.5 | ADO.NET Entity Framework model |
| master | 2.0 | master page file. Default file name is Master1.master |
| resx | 1.0 | resource files for internationalization and localization. Resource files can be global (e.g. messages) or "local" which means specific for one aspx or ascx file. |
| sitemap | 2.0 | sitemap configuration files. Default file name is web.sitemap |
| skin | 2.0 | theme skin files. |
| svc | 3.0 | Windows Communication Foundation service file |
| vbhtml | 4.1 | Views (mixed VB and HTML using Razor syntax) |
In general, the ASP.NET directory structure can be determined by the developer's preferences. Apart from a few reserved directory names, the site can span any number of directories. The structure is typically reflected directly in the URLs. Although ASP.NET provides means for intercepting the request at any point during processing, the developer is not forced to funnel requests through a central application or front controller.
The special directory names (from ASP.NET 2.0 on) are:
ASP.NET aims for performance benefits over other script-based technologies (including classic ASP) by compiling the server-side code to one or more DLL files on the Web server. This compilation happens automatically the first time a page is requested (which means the developer need not perform a separate compilation step for pages). This feature provides the ease of development offered by scripting languages with the performance benefits of a compiled binary. However, the compilation might cause a noticeable but short delay to the Web user when the newly edited page is first requested from the Web server, but will not again unless the page requested is updated further.
The ASPX and other resource files are placed in a virtual host on an Internet Information Services server (or other compatible ASP.NET servers; see Other implementations, below). The first time a client requests a page, the .NET Framework parses and compiles the file(s) into a .NET assembly and sends the response; subsequent requests are served from the DLL files. By default ASP.NET will compile the entire site in batches of 1000 files upon first request. If the compilation delay is causing problems, the batch size or the compilation strategy may be tweaked.
Developers can also choose to pre-compile their "codebehind" files before deployment, using MS Visual Studio, eliminating the need for just-in-time compilation in a production environment. This also eliminates the need of having the source code on the Web server. It also supports pre-compile text.
Microsoft has released some extension frameworks that plug into ASP.NET and extend its functionality. Some of them are:
ASP.NET simplifies developers' transition from Windows application development to Web development by offering the ability to build pages composed of controls similar to a Windows user interface. A Web control, such as a button or label, functions in very much the same way as its Windows counterparts: code can assign its properties and respond to its events. Controls know how to render themselves: whereas Windows controls draw themselves to the screen, Web controls produce segments of HTML and JavaScript which form parts of the resulting page sent to the end-user's browser.
ASP.NET encourages the programmer to develop applications using an event-driven GUI model, rather than in conventional Web-scripting environments like ASP and PHP. The framework combines existing technologies such as JavaScript with internal components like "ViewState" to bring persistent (inter-request) state to the inherently stateless Web environment.
Other differences compared to classic ASP are:
On IIS 6.0 and lower, pages written using different versions of the ASP framework cannot share Session State without the use of third-party libraries. This criticism does not apply to ASP.NET and ASP applications running side by side on IIS 7. With IIS 7, modules may be run in an integrated pipeline that allows modules written in any language to be executed for any request.
Several available software packages exist for developing ASP.NET applications:
| Software | Developer | Licensing |
|---|---|---|
| ASP.NET Intellisense Generator [2] | BlueVision LLC | Free |
| Microsoft Visual Studio | Microsoft | Free and commercial |
| Microsoft Visual Web Developer Express | Microsoft | Registerware |
| CodeGear Delphi | Embarcadero Technologies | Commercial |
| Macromedia HomeSite | Adobe Systems | Commercial |
| Microsoft Expression Web | Microsoft | Free |
| Microsoft SharePoint Designer | Microsoft | Free |
| MonoDevelop | Novell and the Mono community | Free open source |
| SharpDevelop | ICSharpCode Team | Free open source |
| Eiffel for ASP.NET [3] | Eiffel Software | Free open source and commercial |
| Adobe Dreamweaver | Adobe Systems | Commercial |
It is not essential to use the standard Web forms development model when developing with ASP.NET. Noteworthy frameworks designed for the platform include:
The ASP.NET releases history tightly correlates with the .NET Framework releases:
| Date | Version | Remarks | New ASP.NET related features | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| January 16, 2002 | 1.0 | First version released together with Visual Studio .NET |
|
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| April 24, 2003 | 1.1 | released together with Windows Server 2003 released together with Visual Studio .NET 2003 |
|
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| November 7, 2005 | 2.0 |
codename Whidbey |
|
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| November 21, 2006 | 3.0 |
|
||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| November 19, 2007 | 3.5 | Released with Visual Studio 2008 and Windows Server 2008 |
|
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| August 11, 2008 | 3.5 Service Pack 1 | Released with Visual Studio 2008 Service Pack 1 |
|
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| April 12, 2010 | 4.0 |
Parallel extensions and other .NET Framework 4 features |
The two new properties added in the Page class are MetaKeyword and MetaDescription. |
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| August 15, 2012 | 4.5 | Released with Visual Studio 2012 and Windows Server 2012 for Windows 8
Parallel extensions and other .NET Framework 4.5 features |
||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
|
Legend:
Old version
Older version, still supported
Latest version
Future release
|
||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
The Mono Project supports "everything in .NET 4.0 except WPF, EntityFramework and WF, limited WCF." ASP.NET can be run with Mono using one of three options: Apache hosting using the mod_mono module, FastCGI hosting, and XSP.
|
||||||||||||||||||||||||||||
|
|||||||||||||||||||||||||||||||||||||||||||||||||||||
|
|||||||||||||||||||||||||||||||||||||||
|
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
HOT DESIGNS ▪ Premium designs ▪ Designs by country ▪ Designs by U.S. state ▪ Most popular designs ▪ Newest, last added designs ▪ Unique designs ▪ Cheap, budget designs ▪ Design super sale DESIGNS BY THEME ▪ Accounting, audit designs ▪ Adult, sex designs ▪ African designs ▪ American, U.S. designs ▪ Animals, birds, pets designs ▪ Agricultural, farming designs ▪ Architecture, building designs ▪ Army, navy, military designs ▪ Audio & video designs ▪ Automobiles, car designs ▪ Books, e-book designs ▪ Beauty salon, SPA designs ▪ Black, dark designs ▪ Business, corporate designs ▪ Charity, donation designs ▪ Cinema, movie, film designs ▪ Computer, hardware designs ▪ Celebrity, star fan designs ▪ Children, family designs ▪ Christmas, New Year's designs ▪ Green, St. Patrick designs ▪ Dating, matchmaking designs ▪ Design studio, creative designs ▪ Educational, student designs ▪ Electronics designs ▪ Entertainment, fun designs ▪ Fashion, wear designs ▪ Finance, financial designs ▪ Fishing & hunting designs ▪ Flowers, floral shop designs ▪ Food, nutrition designs ▪ Football, soccer designs ▪ Gambling, casino designs ▪ Games, gaming designs ▪ Gifts, gift designs ▪ Halloween, carnival designs ▪ Hotel, resort designs ▪ Industry, industrial designs ▪ Insurance, insurer designs ▪ Interior, furniture designs ▪ International designs ▪ Internet technology designs ▪ Jewelry, jewellery designs ▪ Job & employment designs ▪ Landscaping, garden designs ▪ Law, juridical, legal designs ▪ Love, romantic designs ▪ Marketing designs ▪ Media, radio, TV designs ▪ Medicine, health care designs ▪ Mortgage, loan designs ▪ Music, musical designs ▪ Night club, dancing designs ▪ Photography, photo designs ▪ Personal, individual designs ▪ Politics, political designs ▪ Real estate, realty designs ▪ Religious, church designs ▪ Restaurant, cafe designs ▪ Retirement, pension designs ▪ Science, scientific designs ▪ Sea, ocean, river designs ▪ Security, protection designs ▪ Social, cultural designs ▪ Spirit, meditational designs ▪ Software designs ▪ Sports, sporting designs ▪ Telecommunication designs ▪ Travel, vacation designs ▪ Transport, logistic designs ▪ Web hosting designs ▪ Wedding, marriage designs ▪ White, light designs E-COMMERCE DESIGNS ▪ Magento store designs ▪ OpenCart store designs ▪ PrestaShop store designs ▪ CRE Loaded store designs ▪ Jigoshop store designs ▪ VirtueMart store designs ▪ osCommerce store designs ▪ Zen Cart store designs CMS DESIGNS ▪ Flash CMS designs ▪ Joomla CMS designs ▪ Mambo CMS designs ▪ Drupal CMS designs ▪ WordPress blog designs ▪ Forum designs ▪ phpBB forum designs ▪ PHP-Nuke portal designs ANIMATED WEBSITE DESIGNS ▪ Flash CMS designs ▪ Silverlight animated designs ▪ Silverlight intro designs ▪ Flash animated designs ▪ Flash intro designs ▪ XML Flash designs ▪ Flash 8 animated designs ▪ Dynamic Flash designs ▪ Flash animated photo albums ▪ Dynamic Swish designs ▪ Swish animated designs ▪ jQuery animated designs WEBSITE DESIGNS ▪ WebMatrix Razor designs ▪ HTML 5 designs ▪ Web 2.0 designs ▪ 3-color variation designs ▪ 3D, three-dimensional designs ▪ Artwork, illustrated designs ▪ Clean, simple designs ▪ CSS based website designs ▪ Full design packages ▪ Full ready websites ▪ Portal designs ▪ Stretched, full screen designs ▪ Universal, neutral designs CORPORATE ID DESIGNS ▪ Corporate identity sets ▪ Logo layouts, logo designs ▪ Logotype sets, logo packs ▪ PowerPoint, PTT designs ▪ Facebook themes VIDEO, SOUND & MUSIC ▪ Video e-cards ▪ After Effects video intros ▪ Special video effects ▪ Music tracks, music loops ▪ Stock music bank GRAPHICS & CLIPART ▪ Pro clipart & illustrations, $19/year ▪ 5,000+ icons by subscription ▪ Icons, pictograms |
| Super Offers |
| Super Offers |
| Custom Logo Design $149 ▪ Web Programming ▪ ID Card Printing ▪ Best Web Hosting ▪ eCommerce Software ▪ Add Your Link |
| © 1996-2013 MAGIA Internet Studio ▪ About ▪ Portfolio ▪ Photo on Demand ▪ Hosting ▪ Advertise ▪ Sitemap ▪ Privacy ▪ Maria Online
|
