.NET

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ASP.NET Tips and Tricks Peter Ty Devel
oper Evangelist
.NET and Developer Group
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Agenda

• Development Tips and Tricks
• Error Handling Tips and Tricks
• Production Tips and Tricks

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Development Tips And Tricks File upload

• ASP.NET provides built-in file upload support
• No posting acceptor required
• No third party components required
• Accessible through two APIs
• Request.Files collection
• server control
• HttpPostedFile Object
• HttpPostedFile.InputStream
• HttpPostedFile.ContentType
• HttpPostedFile.FileName
• HttpPostedFile.SaveAs(fileLocation)

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Development Tips And Tricks File upload - Notes

• ASP.NET provides built-in file upload support
• No posting acceptor required
• No third party components required
• Accessible through two APIs
• Request.Files collection
• server control
• HttpPostedFile Object
• HttpPostedFile.InputStream
• HttpPostedFile.ContentType
• HttpPostedFile.FileName
• HttpPostedFile.SaveAs(fileLocation)

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Development Tips And Tricks File upload example

• Sub Btn_Click(Sender as Object, E as EventArgs)
  
  
• UploadFile.PostedFile.SaveAs("c\foo.txt")
• End Sub
• runatserver
  
• Select File To Upload
• runatserver
  
• runatserver/
  

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Demonstration 1File Upload
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Development Tips And Tricks Richer file upload

• File system is not the only option
• Example Storing within SQL
• Access uploaded file as byte array
• Store file within SQL as image (blob)
• Store ContentType and ContentLength also
• Provide Edit Link to display page
• Edit Link Page sets ContentType header and then
  writes binary array back to client

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Demonstration 2File Upload With SQL
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Development Tips And Tricks Image generation

• Rich server image generation
• Additionally supports resizing cropping
• Overlays on top of existing images
• Read/Write Any Standard IO Stream
• System.Drawing
• Dynamically generate GIFs/JPGs from .aspx
• Set ContentType appropriately
• Optionally output cache results

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Demonstration 3Image Generation
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Development Tips And Tricks ASP.NET XML Server
Control

• ASP.NET
• Enables output of XML
• Enables optional XSL/T transform of XML
• Binding options
• File system
• Database item
• Built-in caching
• Ensure efficient re-use
• Improves performance

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Development Tips And Tricks file sample

• DocumentSource"SalesData.xml"
• TransformSource"SalesChart.xsl"
• runatserver /

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Demonstration 4Static XML
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Development Tips And Tricks data sample

• Sub Page_Load(Sender as Object, E as
  EventArgs)
  
• Dim conn as New SqlConnection(connectionStri
  ng)
  
• Dim cmd as New SqlDataAdapter(select
  from products", conn)
  
• Dim dataset As New DataSet()
• cmd.Fill (dataset, "dataset")
• Dim XmlDoc as XmlDocument New
  XmlDataDocument(dataset)
  
• MyXml1.Document XmlDoc
• End Sub

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Demonstration 5Dynamically Bind XML
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Development Tips And Tricks App settings

• Application specific settings
• Stored in web.config files
• Enables devs to avoid hard-coding them
• Administrators can later change them
• Examples
• Database Connection String
• MSMQ Queue Servers
• File Locations

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Development Tips And Tricks App settings steps

• Create web.config file in app vroot
• To return value
• Configuration.AppSettings(dsn)

sn valuelocalhostuidsapwdDataba
sefoo/

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Demonstration 6Application Settings
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Development Tips And Tricks Cookieless sessions

• Session State no longer requires client cookie
  support for SessionID
  
• Can optionally track SessionID in URL
• Requires no code changes to app
• All relative links continue to work

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Development Tips And Tricks Cookieless sessions
steps

• Create web.config file in app vroot
• Add following text

ssionState cookielesstrue/


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Development Tips And Tricks Smart navigation

• Eliminates browser flicker/scrolling on browser
  navigation
  
• Smooth client UI but with server code
• Automatic down-level for non-IE browsers
• No client code changes required
• Alternatively set in web.config file

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Agenda

• Development Tips and Tricks
• Error Handling Tips and Tricks
• Production Tips and Tricks

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Error Handling Tips And Tricks Page tracing

• ASP.NET supports page and app tracing
• Easy way to include debug statements
• No more messy Response.Write() calls!
• Great way to collect request details
• Server control tree
• Server variables, headers, cookies
• Form/Querystring parameters

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Error Handling Tips And Tricks Page tracing steps

• Add trace directive at top of page
• Add trace calls throughout page
• Trace.Write(Button Clicked)
• Trace.Warn(Value value)
• Access page from browser

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Demonstration 7Page Tracing
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Error Handling Tips And Tricks Application
tracing steps

• Create web.config file in app vroot
• Access tracing URL within app
• http//localhost/approot/Trace.axd

ce enabledtrue requestLimit10/


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Demonstration 8Application Tracing
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Error Handling Tips And Tricks Error handling

• .NET provides unified error architecture
• Runtime errors done using exceptions
• Full call stack information available w/ errors
• Can catch/handle/throw exceptions in any .NET
  Language (including VB)
  
• ASP.NET also provides declarative application
  custom error handling
  
• Enable programmatic logging of problems
• Automatically redirect users to error page when
  unhandled exceptions occur

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Error Handling Tips And Tricks Error handling -
Notes

• .NET provides unified error architecture
• Runtime errors done using exceptions
• Full call stack information available w/ errors
• Can catch/handle/throw exceptions in any .NET
  Language (including VB)
  
• ASP.NET also provides declarative application
  custom error handling
  
• Enable programmatic logging of problems
• Automatically redirect users to error page when
  unhandled exceptions occur

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Error Handling Tips And Tricks Application_Error

• Global application event raised if unhandled
  exception occurs
  
• Provides access to current Request
• Provides access to Exception object
• Enables developer to log/track errors
• Cool Tip
• Use new EventLog class to write custom events to
  log when errors occur
  
• Use new SmtpMail class to send email to
  administrators

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Demonstration 9Writing to NT Event Log
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Error Handling Tips And Tricks Sending SMTP mail


Sub Application_Error(sender as Object, e as
EventArgs) Dim MyMessage as New MailMe
ssage MyMessage.To someone_at_microsoft
.com" MyMessage.From "MyAppServer"
MyMessage.Subject "Unhandled Error!!!"
MyMessage.BodyFormat MailFormat.Html
MyMessage.Body "" Re
quest.Path _ "" Me.Error.ToString()
"" SmtpMail.Send(MyMessag
e) End Sub
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Error Handling Tips And Tricks Custom errors

• Enable easy way to hide errors from end-users
  visiting a site
  
• No ugly exception error messages
• Enables you to display a pretty site under
  repair page of your design
  
• Custom Errors configured within an application
  web.config configuration file
  
• Can be configured per status code number
• Can be configured to only display remotely

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Error Handling Tips And Tricks Custom error page
steps

• Create web.config file in app vroot

s moderemoteonly defaultRed
irecterror.htm redirectadminmessage.htm/
noaccessallowed.htm/ /system.web
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Demonstration 10Custom Errors
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Agenda

• Development Tips and Tricks
• Error Handling Tips and Tricks
• Production Tips and Tricks

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Production Tips And Tricks Performance counters

• Per Application Performance Counters
• Enable easily monitoring of individual ASP.NET
  applications
  
• Custom Performance Counters APIs
• Now possible to publish unique application-specifi
  c performance data
  
• Great for real-time application monitoring
• Example total orders, orders/sec

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Demonstration 11Performance Counters
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Production Tips And Tricks Process model recovery

• ASP.NET runs code in an external worker process
  aspnet_wp.exe
  
• Automatic Crash Recovery
• Automatic Memory Leak Recovery
• Automatic Deadlock Recovery
• Can also proactively configure worker process to
  reset itself proactively
  
• Timer based
• Request based

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Production Tips And Tricks Reliable session state

• Session State can now be external from ASP.NET
  Worker Process
  
• ASPState Windows NT Service
• SQL Server
• Big reliability wins
• Session state survives crashes/restarts
• Enables Web farm deployment
• Multiple FE machines point to a common state store

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Production Tips And Tricks External session
state steps

• Start ASP State Service on a machine
• net start aspnet_state
• Create web.config file in app vroot, and point
  it at state service machine

e modeStateServer
stateConnectionStringtcpipserverport /

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For More Information

• MSDN Web site at
• msdn.microsoft.com
• ASP.NET Quickstart at
• http//www.asp.net
• 900 samples that can be run online
• ASP.NET discussion lists
• For good best practice reference applications,
  please visit IBuySpy
  
• http//www.IBuySpy.com

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