Silverlight Debugging

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Silverlight Debugging

• Alan Cobb
• Independent .NET Consultant
• Alan Cobb Associates, Inc.
• Sacramento, CA
• Silicon Valley Code Camp 2008
• Saturday, November 8, 2008, 345pm

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About Alan Cobb

• Independent consultant for over 20 years on
  Microsoft platforms
• Silverlight, WPF, .NET, C, C
• One of directors of the SacDotNet User Group
• http//www.alancobb.com
• http//www.alancobb.com/blog

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Another Code Camp Session

• WCF Debugging Where Do I Start
• Presented by Petar Vucetin
• 915AM Sunday Room 4204
• See also Web Service debugging section of
  Silverlight documentation
• Debugging Services for Silverlight Applications

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Presentation Overview

• Beginning
• Setting up VS2008 for SL debugging
• Alternatives for SL tracing
• Intermediate
• SL debugging tools Fiddler, Silverlight Spy
• Advanced
• Performance debugging
• SOS extension Low level .NET debugging

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Description on Website

• This session will survey a range of Silverlight 2
  debugging tools and techniques. At the beginner
  level well review setting up VS2008 for
  debugging Silverlight C and JavaScript code.
  Then well look at different techniques for trace
  logging. At an intermediate level well cover
  three debugging tools I use extensively Fiddler,
  Silverlight Spy and NetLimiter. At the advanced
  level well do some low-level Silverlight .NET
  debugging with WinDbg and the SOS debugger
  extension DLL. SOS helps you hunt for memory
  leaks by giving you a detailed view of the
  managed heap. Stack traces from SOS can sometimes
  reveal more about the context of bugs than VS2008
  can.

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Beginning Level Issues

• Setting up VS 2008 for SL debugging
• Know where the settings are
• Turn on 1st chance exception handling
• Alternatives for Tracing in SL
• Debug.WriteLine and DebugView
• Clog for Silverlight

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Setting up VS2008

• Use a Web Application Project
• Turn on 1st chance exception handling
• Where are the settings?
• VS itself, Your project, Web.config, Internet
  Explorer
• Types of breakpoints
• JS, .NET client and server side

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Turn on break when exception thrown
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Turn on break when exception thrown
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Which code? Running Where?
Client
Server
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Main Silverlight DLLs
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SL Tracing Debug.WriteLine
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SL Tracing DebugView
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SL Tracing DebugView
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SL2 Tracing CLog
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Fiddler

• What is it?
• HTTP proxy server
• What can you do with it?
• Watching browser talk to Silverlight sites
• Debugging cross domain policy file issues
• Timing analysis (slow connection tests)

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Fiddler Watch HTTP conversation
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Reflector
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Getting generic.xaml with Reflector
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Fiddler Demo Little Loader App
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Fiddler Slow Connection Testing
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Fiddler Download Timing Analysis
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Silverlight Spy

• How is Silverlight Spy constructed?
• Features
• Browse Silverlight element tree
• Fly over element tree
• See element statistics
• Copy XAML for a given branch
• Modify element properties interactively
• Other

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Demo Silverlight Spy
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Debugging Performance Issues

• Seema Ramchandanis PDC2008 talk
• FrameRate
• Host.Settings.MaxFrameRate
• Host.Settings.EnableFrameRateCounter
• CompositionTarget.Rendering event
• Host.Settings.EnableRedrawRegions
• Profiling
• Xperf ? (A free profiler from MS)

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Performance The Render Loop
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Performance Instrumentation Demo
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SOS Low-level .NET Debugging

• What is SOS?
• Extension DLL for WinDbg debugger
• Downloading WinDbg setting up SOS
• Intro articles on Silverlight and SOS 1, 2
• Pointing at Microsoft symbol server
• What can you use it for?
• Examine Silverlights managed heap
• Get more detailed stack traces

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SOS Where is SOS.DLL?
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SOS Demo Exception and Hang
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SOS Demo Detailed Stack Traces
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SOS Demo Finding Memory Leak
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SOS Demo Finding Memory Leak