2. Understanding ASP.NET Under The Covers
Miguel A. Castro
Architect
IDesign
Level 200

3. Agenda Defining ASP.NET Terms & Buzzwords
A Request-to-Response Walkthrough
Additional Technologies
Summary

4. Your Speaker Miguel A. Castro ineta
.NET Architect, Developer, & Trainer
Microsoft MVP
ASP Insider
Member of the INETA Speakers Bureau
Conference Speaker
Creator of CodeBreeze
In IT business since 1986
ineta

5. Agenda Defining ASP.NET Terms & Buzzwords
A Request-to-Response Walkthrough
Additional Technologies
Summary

6. Classic ASP Interpreted language
Included embedded scripting code mixed into HTML
Limited to VBScript
Ran in the same process as IIS
Inherently not scalable (needed MTS)
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7. Walking Upright Designed by Scott Guthrie & Mark Anders
Early iteration of ASP.NET
Originally known as XSP
Not .NET-related – Java based !
Became ASP+ with the design of the CLR
Rewritten in C#
Renamed when .NET branding introduced
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8. Not a language ! What is ASP.NET
A framework for developing and delivering information & applications on the web.
Known primarily as a page framework.
A complete Request/Response management system.
Can handle and respond to all sorts of requests on the Internet (or an Intranet).
Not a language !
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9. Characteristics of ASP.NET
Runs under its own worker process.
No longer tied to IIS.
Code execution managed by CLR.
Code-Behind model allows code separation.
Includes state handling facilities.
Provides caching functionality.
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10. Agenda Defining ASP.NET Terms & Buzzwords
A Request-to-Response Walkthrough
Additional Technologies
Summary

11. Commonly Used Terms Request Response ASP.NET Pipeline
An HTTP query initiated by a client to a server for the purpose of performing some action.
Response
A stream of information sent back to a client from the HTTP server that processed the client’s request.
ASP.NET Pipeline
A series of extensible functionality points which continue the process of a request in order to eventually obtain a response.
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12. Commonly Used Terms Page Lifecycle Control Model
Another series of functionality points that form the process of converting an ASPX page to HTML output.
The entire page lifecycle occurs between two pipeline points.
Control Model
The heart of how ASP.NET builds HTML from compiled classes that represent visual components.
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13. Agenda Defining ASP.NET Terms & Buzzwords
A Request-to-Response Walkthrough
Additional Technologies
Summary

14. What Everyone Sees Now the long version… Desktop Browser
Web Server (IIS)
Convert ASPX to HTML
Rendered HTML
Now the long version…
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15. Getting it to .NET (the low level stuff)
Kernel Mode Driver: Http API used by IIS
Web Server (IIS)
Web Server (IIS)
Convert ASPX to HTML
http.sys
Worker Process started (one per pool) and if needed, AppDomain is created.
Worker Process (w3wp.exe) – (one per app pool)
aspnet_isapi.dll
Attached to the extension of the request.
Unmanaged DLL that loads the CLR and routes requests to the managed runtime classes via COM-compliant interfaces.
AppDomain
(one per site/VD)
ISAPIRuntime (ProcessRequest method)
HttpRuntime. ProcessRequest
Request sent to the ASP.NET runtime for processing.
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16. HttpRuntime.ProcessRequest
ASP.NET Takes Over
HttpRuntime.ProcessRequest
Accessible from now until the end of the request processing. Accessible through HttpContext.Current
HttpContext created.
This serves as an entry point into the request, response, and other accessible variables.
Each AppDomain manages multiple instances so they do not conflict with each other (different users or same user with more than one request).
An HttpApplication instance is created.
HttpApplication
This is where it starts to mean something to you, the developer.
Init method starts pipeline processing.
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17. Entering the Pipeline HttpApplication
Pipeline kicked off in the Init method.
HttpApplication
BeginRequest
Performs event processing.
AuthenticateRequest / Post
AuthorizeRequest / Post
Checks hooks from Global.asax class.
ResolveRequestCache / Post
Checks hooks from external HTTP Modules.
MapRequestHandler / Post
AcquireRequestState / Post
PreRequestHandlerExecute / Post
ReleaseRequestState / Post
UpdateRequestCache / Post
LogRequest / Post
EndRequest
PreSendRequestHeaders
PreSendRequestContent
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18. Entering the Pipeline HttpApplication BeginRequest
AuthenticateRequest / Post
AuthorizeRequest / Post
ResolveRequestCache / Post
MapRequestHandler / Post
AcquireRequestState / Post
PreRequestHandlerExecute / Post
ReleaseRequestState / Post
UpdateRequestCache / Post
LogRequest / Post
EndRequest
PreSendRequestHeaders
PreSendRequestContent
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19. Pipeline Events of Interest
HttpApplication
Provide URL-Rewriting functionality.
BeginRequest
AuthenticateRequest / Post
Repopulate HttpContext.Current.User with stored principal.
Page authentication occurs here.
AuthorizeRequest / Post
ResolveRequestCache / Post
MapRequestHandler / Post
AcquireRequestState / Post
PreRequestHandlerExecute / Post
Determine whether to use cached response.
ReleaseRequestState / Post
UpdateRequestCache / Post
Any event can be hooked in Global.asax or in an HTTP Module.
LogRequest / Post
EndRequest
PreSendRequestHeaders
PreSendRequestContent
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20. MyModule : IHttpModule
HTTP Modules
Classes that implement IHttpModule.
MyModule : IHttpModule
Delegate-based Properties in HttpApplication instance can be wired up.
Method functionality equivalent to hooking event in Global.asax
Event hooks in modules checked during pipeline processing.
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21. ASP.NET HTTP Modules of Interest
WindowsAuthenticationModule
FormsAuthenticationModule
UrlAuthenticationModule
FileAuthorizationModule
ServiceModel
SessionStateModule
OutputCacheModule
AuthenticateRequest
AuthenticateRequest
EndRequest
AuthorizeRequest
AuthorizeRequest
PostAuthenticateRequest
AcquireRequestState
AcquireRequestState
ReleaseRequestState
EndRequest
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22. Any level in the Config chain
Module Installation
Any level in the Config chain
You do know what the Config chain is, right?
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23. The Process Continues
HttpApplication
Just before this event:
Proper HTTP Handler located based on request’s extension.
BeginRequest
AuthenticateRequest / Post
Handlers provide necessary processing in order to create a response.
AuthorizeRequest / Post
ResolveRequestCache / Post
MapRequestHandler / Post
AcquireRequestState / Post
PreRequestHandlerExecute / Post
ReleaseRequestState / Post
UpdateRequestCache / Post
LogRequest / Post
EndRequest
PreSendRequestHeaders
PreSendRequestContent
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24. MyHandler : IHttpHandler
HTTP Handlers
Classes that implement IHttpHandler.
Determines if the handler instance can be reused by another request.
MyHandler : IHttpHandler
Functionality assigned to this particular handler.
Remember the HttpContext contains all accessible variables, including Response.
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25. HTTP Handler Factories
Can also implement IHttpHandlerFactory.
Allows the instantiation of any handler based on specific conditioning scenarios.
MyHandlerFactory : IHttpHandlerFactory
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26. Characteristics of an HTTP Handler
Access to current HttpContext.
Request is in there (as is the Response) !
Handlers are wired to extensions (aspx, etc.).
Every handler is responsible for what the response is going to be for a request.
ASPX requests expect an HTML response.
Config requests expect a “forbidden” response.
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27. Handler Execution HttpApplication BeginRequest
AuthenticateRequest / Post
AuthorizeRequest / Post
The determined handler is processed between the PreRequestHandlerExecute and PostRequestHandlerExecute.
ResolveRequestCache / Post
MapRequestHandler / Post
AcquireRequestState / Post
PreRequestHandlerExecute / Post
ReleaseRequestState / Post
UpdateRequestCache / Post
LogRequest / Post
EndRequest
PreSendRequestHeaders
PreSendRequestContent
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28. Any level in the Config chain
Handler Installation
Handler factory that returns and executes the handler that will convert an ASPX page to HTML output.
Any level in the Config chain
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29. The PageHandlerFactory Class
Implements IHttpHandlerFactory.
GetHandler method returns an IHttpHandler in the form of System.Web.UI.Page-derived class hierarchy.
Page class implements IHttpHandler.
Page class inherits from Control.
Control contains events/methods for the “Page Event Lifecycle”.
PageHandlerFactory creates a class structure out of your request.
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30. Page Class Structure Created by the PageHandlerFactory class
Follows the structure of an ASP.NET Server Control.
Referred to as Page-Gen Class.
Created by the PageHandlerFactory class
Virtual class created from ASPX page.
Controls created based on ASPX content.
inherits
Partial class with control declarations (class name same as code-behind).
partials with
Code-behind class is other side of partial class.
This is why you can tap into events from your code-behind.
inherits
ProcessRequest method calls lifecycle events in Control.
System.Web.UI.Page
inherits
implements
System.Web.UI.Control
IHttpHandler
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31. Page Class Structure Created by the PageHandlerFactory class
Virtual class created from ASPX page.
inherits
Partial class with control declarations (class name same as code-behind).
partials with
Code-behind class is other side of partial class.
inherits
System.Web.UI.Page
inherits
implements
System.Web.UI.Control
IHttpHandler
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32. Virtual Class Created from ASPX content
Determines language to be used to generate page-gen class.
Specifies the partial class to serve as the code-behind.
Optional:
Name of the code-file for Visual Studio.
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33. Virtual Class Created from ASPX content LiteralControl
Converted to instances of System.Web.UI.LiteralControl
that are added to the control tree of this class.
Remember, this class will ultimately inherit from System.Web.UI.Control
LiteralControl
LiteralControl
LiteralControl
LiteralControl
LiteralControl
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34. Program code directly added to virtual class.
Created from ASPX content
LiteralControl
LiteralControl
Program code directly added to virtual class.
LiteralControl
LiteralControl
LiteralControl
LiteralControl
LiteralControl
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35. Virtual Class Created from ASPX content LiteralControl
Converted to instances of the corresponding server control class for each of these control tags, that will be added to the control tree of this class.
LiteralControl
The Form control instance is placed directly in the control tree of the class being created; while the TextBox and Label controls are added to the control tree of the Form control.
LiteralControl
LiteralControl
LiteralControl
LiteralControl
LiteralControl
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36. Virtual Class Created from ASPX content LiteralControl
“asp” tag-prefix located in config file or Register directive.
LiteralControl
Class with tag name located in appropriate namespace and assembly.
LiteralControl
LiteralControl
LiteralControl
LiteralControl
LiteralControl
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37. Remember: this class “ultimately” inherits from System.Web.UI.Page
Virtual Class
Created from ASPX content
__PAGE System.Web.UI.Page
LiteralControl
ctrl0 System.Web.UI.LiteralControl
LiteralControl
Function Code
Remember: this class “ultimately” inherits from System.Web.UI.Page
ctrl1 System.Web.UI.LiteralControl
form1 System.Web.UI.HtmlControls.HtmlForm
LiteralControl
ctrl2 System.Web.UI.LiteralControl
Control IDs
TextBox1 System.Web.UI.WebControls.TextBox
LiteralControl
ctrl3 System.Web.UI.LiteralControl
LiteralControl
Label1 System.Web.UI.WebControls.Label
ctrl4 System.Web.UI.LiteralControl
LiteralControl
ctrl5 System.Web.UI.LiteralControl
LiteralControl
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38. This is the next class you’ll see now.
Virtual Class
Created from ASPX content
LiteralControl
LiteralControl
This is the next class you’ll see now.
LiteralControl
LiteralControl
LiteralControl
LiteralControl
LiteralControl
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39. Page rendering with Trace
11/29/2018 7:58 AM
demo
If you would like to host your demo on the Virtual Server, please use the myVPC demo slide, not this slide.
Page rendering with Trace
© 2007 Microsoft Corporation. All rights reserved. Microsoft, Windows, Windows Vista and other product names are or may be registered trademarks and/or trademarks in the U.S. and/or other countries.
The information herein is for informational purposes only and represents the current view of Microsoft Corporation as of the date of this presentation. Because Microsoft must respond to changing market conditions, it should not be interpreted to be a commitment on the part of Microsoft, and Microsoft cannot guarantee the accuracy of any information provided after the date of this presentation. MICROSOFT MAKES NO WARRANTIES, EXPRESS, IMPLIED OR STATUTORY, AS TO THE INFORMATION IN THIS PRESENTATION.

40. Page Class Structure Created by the PageHandlerFactory class
Virtual class created from ASPX page.
inherits
Partial class with control declarations (class name same as code-behind).
partials with
Code-behind class is other side of partial class.
inherits
System.Web.UI.Page
inherits
implements
System.Web.UI.Control
IHttpHandler
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41. Notice the name is the same as the page’s code-behind class.
Partial Class
Base for virtual class and partial to code-behind
Notice the name is the same as the page’s code-behind class.
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42. Page Class Structure Created by the PageHandlerFactory class
Virtual class created from ASPX page.
inherits
Partial class with control declarations (class name same as code-behind).
partials with
Code-behind class is other side of partial class.
inherits
System.Web.UI.Page
inherits
implements
System.Web.UI.Control
IHttpHandler
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43. Inheriting from Page gives you access to a control’s event lifecycle.
Code-Behind Class
Other side of the Control Declarations class
Inheriting from Page gives you access to a control’s event lifecycle.
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44. Page Class Structure Created by the PageHandlerFactory class
Virtual class created from ASPX page.
Remember, this entire class hierarchy is the handler returned by the PageHandlerFactory class.
It is the HttpApplication pipeline that calls ProcessRequest, kicking off the Page Lifecycle.
inherits
Partial class with control declarations (class name same as code-behind).
ProcessRequest comes from here. It is from there that the lifecycle events are called.
Events for the lifecycle come from here.
partials with
Code-behind class is other side of partial class.
inherits
System.Web.UI.Page
inherits
implements
System.Web.UI.Control
IHttpHandler
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45. Page (Control) Lifecycle
Complete List
PreInit
Init
InitComplete
CreateChildControls (IsPostBack)
LoadViewState/LoadControlState
IPostBackDataHandler.LoadPostData
PreLoad
Load
IPostBackDataHandler.RaisePostBackChangedEvent
IPostBackEventHandler.RaisePostBackEvent
LoadComplete
CreateChildControls (!IsPostBack)
PreRender
DataBind
PreRenderComplete
SaveViewState/SaveControlState
Render
Unload
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46. Most Commonly Known Points
Initialize: OnInit method and Init event
Begin tracking ViewState: TrackViewState method
Postback only
Load View State: LoadViewState method
Load Postback Data: IPostBackDataHandler.LoadPostdata method
Load: OnLoad method and Load event
Raise Changed Events: IPostBackDataHandler.RaisePostBackChangedEvent method
Raise Postback Event: IPostBackEventHandler.RaisePostBackEvent method
PreRender: OnPreRender method and PreRender event
Save View State: SaveViewState method
Render: Render method
Unload: OnUnload method and Unload event
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47. Control Rendering Activated through the Control class’ Render method.
Each control is designed to output something to the response buffer.
Most controls output HTML.
Some controls contain others in their tree.
Control rendering involves recursively rendering child controls.
Controls don’t need to output anything
ScriptManager
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48. Getting a Response
“Rendering” uses an HtmlTextWriter stored in the Response object.
Response object is part of HttpContext.
Writer sent into Render method.
After pipeline complete, contents returned up the chain to aspnet_isapi.dll then http.sys.
Results viewed on browser.
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49. Agenda Defining ASP.NET Terms & Buzzwords
A Request-to-Response Walkthrough
Additional Technologies
Summary

50. Postbacks Invoked by controls on form that trigger the form to “post”.
Another HTTP Request, but of a post-type.
Certain lifecycle methods only invoked on postback only.
In a postback, the Request object’s Form property contains posted data from HTML elements (using their client IDs).

51. Postbacks Initialize: OnInit method and Init event
Begin tracking ViewState: TrackViewState method
Postback only
Load View State: LoadViewState method
Load Postback Data: IPostBackDataHandler.LoadPostdata method
Load: OnLoad method and Load event
Raise Changed Events: IPostBackDataHandler.RaisePostBackChangedEvent method
Raise Postback Event: IPostBackEventHandler.RaisePostBackEvent method
PreRender: OnPreRender method and PreRender event
Save View State: SaveViewState method
Render: Render method
Unload: OnUnload method and Unload event
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52. ASCX User Controls
Register directive defines tag prefix and name for user control.
src points to an ascx file in the current web application.
During parsing, virtual class is built just like a page, except the base is called UserControl.
Also, added to Page’s Controls collection.
UserControl also inherits from Control but does NOT implement IHttpHandler.
Usage in an ASPX page (or another ASCX control) is just like a server control.
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53. Master Pages
Code-Behind class inherits from MasterPage, which inherits from UserControl.
Master directive similar to a Page directive.
ASPX page points to a master page file.
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54. Master Pages
Control that specifies content to be defined in an ASPX page.
Control that wraps content.
Each Content control corresponds to a ContentPlaceHolder control.
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55. Master Pages Desktop Browser Browse to Default.aspx Web Server (IIS)
PageHandlerFactory commences building of virtual class.
MasterPageFile attribute encountered.
Parsing shifts to master page file and code-behind.
Control tree build and added to virtual class.
Parsing returns to ASPX page and Content controls turned to code.
Each Content control added to the Controls collection of corresponding ContentPlaceHolder control.
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56. Note: you cannot browse directly to an ASCX control or a Master page.
Direct Browsing
Note: you cannot browse directly to an ASCX control or a Master page.
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57. SimpleHandlerFactory in charge of returning HTTP Handler.
ASHX Handlers
SimpleHandlerFactory in charge of returning HTTP Handler.
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58. ProcessRequest called in the pipeline as always.
ASHX Handlers
PageHandlerFactory:
Parses ASPX file, building virtual class as an HTTP Handler, with ProcessRequest kicking off page lifecycle.
SimpleHandlerFactory:
Takes this handler code and returns is as HTTP Handler.
ProcessRequest called in the pipeline as always.
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59. Themes & Skins
Contain server control declarations (without IDs) whose properties overwrite those declared on the ASPX page.
Control “registration” applies.
Either in skin file or in config file.
Applied just before Init lifecycle event.
Programmatic application MUST be made in PreInit event.
Application using Theme attribute occurs last.
Application using StyleSheetTheme attribute occurs first.
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60. ASP.NET Ajax More interactive model.
Uses JavaScript to invoke Ajax requests.
Web Service (WCF) technology can be used to handle response.
Ships with controls and components that encapsulate functionality.
Ajax Control Toolkit – ships separately
Community driven and supported
Undergoes Microsoft Scrutiny
Better user experience.
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61. ASP.NET MVC Process nearly identical to conventional ASP.NET.
It’s still ASP.NET
Uses a URL routing engine to parse URLs and invoke appropriate classes.
Pipeline is intercepted by a module tapping into PostResolveRequestCache event.
Request is picked up by another handler for processing.
Controller classes are sought out and processed (similar to code-behind classes).
Appropriate Views parsed and rendered.
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62. Why Custom Modules Background processes URL rewriting
Identity persistence for custom providers (or any other kind of persistence)
Benchmarking

63. Why Custom Handlers Image watermarking Dynamic image generation
RSS output generation
File denial or protection

64. Tips & Tricks Use your own base page to house common functionality.
If overriding On{event} methods, remember that the event-wire-up methods in code-behind fire when you call base On{event}.
Example: override OnLoad in a base class, Page_Load in code-behind gets called when you call base.OnLoad.
Use <page pageBaseType= demo
Register your server controls in your Web.Config file.
Eliminates repeat registrations in ASPX & ASCX files.
Eliminates registrations in Skin files.
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65. Tips & Tricks Remove HTTP Modules that you don’t need
If file protection necessary, add file extension (ZIP) to registered extensions in IIS.
Bring them into the pipeline for protection and controlled exposure.
Presentation available on my site.
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66. Tips & Tricks
Turn ViewState off in controls that don’t need them – especially grids.
In 4.0 the model can be reversed.
More compact in 4.0.
Override LoadPageStateFromPersistenceMedium & SavePageStateToPersistenceMedium to alter where and how ViewState is saved.

67. Tips & Tricks Deployment Mode Way Advanced In <system.web>
<deployment retail=“true” />
Turns debugging, tracing, and detailed errors OFF
Machine.Config ONLY
Way Advanced
PageParserFilter abstract base class
Lets you govern the behavior of the ASP.NET Page Parser

68. demo Various tips & tricks 11/29/2018 7:58 AM
If you would like to host your demo on the Virtual Server, please use the myVPC demo slide, not this slide.
Various tips & tricks
© 2007 Microsoft Corporation. All rights reserved. Microsoft, Windows, Windows Vista and other product names are or may be registered trademarks and/or trademarks in the U.S. and/or other countries.
The information herein is for informational purposes only and represents the current view of Microsoft Corporation as of the date of this presentation. Because Microsoft must respond to changing market conditions, it should not be interpreted to be a commitment on the part of Microsoft, and Microsoft cannot guarantee the accuracy of any information provided after the date of this presentation. MICROSOFT MAKES NO WARRANTIES, EXPRESS, IMPLIED OR STATUTORY, AS TO THE INFORMATION IN THIS PRESENTATION.

69. Agenda Defining ASP.NET Terms & Buzzwords
A Request-to-Response Walkthrough
Additional Technologies
Summary

70. What To Take Away From This
ASP.NET does much more than serve pages.
Decoupled architecture allows flexible hosting.
Pipeline and Event cycle – two different things.
Extensible architecture allows opportunities for interception and alteration.
Module and Handler model enforce encapsulation and reusability.
Be mindful of how much is happenning behind the scenes.
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71. References Great Wikipedia entry Article: How ASP.NET Works
Article: How ASP.NET Works
Code Magazine – Nov/Dec 2005
Rick Strahl

72. References Article: Truly Understanding ViewState
Dave Reed
Understanding ASP.NET Internals
Rob Howard

73. References Essential ASP.NET 2.0 My Site & Email: www.codeplex.com
Addison-Wesley
Fritz Onion & Keith Brown
My Site &

74. Tech-Ed 2009 is NOT producing a DVD
IMPORTANT:
Tech-Ed 2009 is NOT producing a DVD

75. Resources www.microsoft.com/teched www.microsoft.com/learning
Sessions On-Demand & Community
Microsoft Certification & Training Resources
Resources for IT Professionals
Resources for Developers
Microsoft Certification and Training Resources

76. Complete an evaluation on CommNet and enter to win!

77. 11/29/2018 7:58 AM
© 2009 Microsoft Corporation. All rights reserved. Microsoft, Windows, Windows Vista and other product names are or may be registered trademarks and/or trademarks in the U.S. and/or other countries.
The information herein is for informational purposes only and represents the current view of Microsoft Corporation as of the date of this presentation. Because Microsoft must respond to changing market conditions, it should not be interpreted to be a commitment on the part of Microsoft, and Microsoft cannot guarantee the accuracy of any information provided after the date of this presentation. MICROSOFT MAKES NO WARRANTIES, EXPRESS, IMPLIED OR STATUTORY, AS TO THE INFORMATION IN THIS PRESENTATION.
© 2007 Microsoft Corporation. All rights reserved. Microsoft, Windows, Windows Vista and other product names are or may be registered trademarks and/or trademarks in the U.S. and/or other countries.
The information herein is for informational purposes only and represents the current view of Microsoft Corporation as of the date of this presentation. Because Microsoft must respond to changing market conditions, it should not be interpreted to be a commitment on the part of Microsoft, and Microsoft cannot guarantee the accuracy of any information provided after the date of this presentation. MICROSOFT MAKES NO WARRANTIES, EXPRESS, IMPLIED OR STATUTORY, AS TO THE INFORMATION IN THIS PRESENTATION.