Wp7 performance challenges
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This document discusses various performance challenges when developing Windows Phone 7 apps. It covers challenges with networking and serialization affecting the UI thread, slow performance of large ListBoxes, benefits of using bitmap caching over redrawing images, and techniques for optimizing computationally intensive apps including avoiding overloading the UI thread. Overall it provides guidance on profiling apps and techniques for improving performance through optimizations like caching, throttling updates, and testing on actual devices.
Wp7 performance challenges
- 2. WP7 Performance ChallengesMy ExperienceEveryday performance challengesVisually rich app performancechallengesComputing intense performance challenges
- 5. Cocktail Flow ChallengesSerialization / DeserilaizationAnimationsDownloading packages: networkingRich ListBoxesEmulator vs physical device
- 6. Visiblox Charts for WP7
- 7. Visiblox Charts for WP7 ChallengesAvoiding overloading of the UI threadRealtime drawing on the screenHow fast can you draw on the phone?Memory LeaksData bindingDPs
- 9. Networking & the UIQuestion
- 10. Networking & the UIWebClient: simple, easy… runs on the UI thread!HttpWebRequest: complicated &performant
- 12. Serialization & DeserializationBinary SerializationDataContractSerializerJson.NETsharpSerializerMike Talbot’s Silverlight SerializerSterling Isolated Storage DBNinja Database Pro
- 14. ListBoxCool in the beginningRusty when you start adding stuffAwfully slow when you start tweaking visualsPain to make it half as fast as on the iPhone
- 15. ListBoxSlow with > 50-200 elementsVirtualized, but….Several workaroundsWindows Phone Team: ListBox best practices3rd party Listbox (Telerik)Implement paging
- 16. Emulator vs Physical DeviceEmulator usually 2-5x times fasterGPU intensive tasks: emulator can be slowerTest (frequently) on the device
- 17. Small ThingsProgressBarSplashscreen while loading PerformanceProgressBar
- 18. Visually Rich App Performance Challenges
- 19. Frame Rate CountersFPS (render > 30, UI > 15)Texture mem. usageFill Rate (<2.5)Blog post explaining these
- 20. BitmapCachevs No CachingNo caching GUP calculates every timeBitmapCache “screenshot” saved, no GPU needed
- 22. Image Do’s and Don’t‘sFast (with BitmapCache):Transforms: Scale, Rotate, TranslateOpacitiy changeClipping region changeSlowChanging image with / heightOpacityMaskNon-rectangular clipping areasJpegs are (somewhat) faster than pngs
- 24. Avoid Overloading the UI ThreadUse BackgroundWorkerThrottle calls to UI while it’s busyvia the “render loop”:E.g a chart is redrawn whenever the Zoom changesA chart redraw takes 100msThe Zoom is changed at 0ms, 40ms, 80ms, 120msThe chart will still be drawing at 40ms & 80ms!
- 25. Rendering Real-TimeLightweight vs heavyweight elementsShapes vs Controls vsUserControlsDrawing is more expensive than redrawingReuse existing elementsWriteableBitmap & WriteableBitmapExWorking with large Paths: buggy, slow
- 26. Extreme OptimalizationsData BindingAvoid when there are thousands of objectsTakes up memory & notifications may fire too oftenDPsOnly use if neededSlow to read cache in CLR properties
- 27. SummaryNetworking & effect on UI threadSerialization & deserializationListBoxBitmapCaching
- 28. Closing ThoughtsUse the performance countersPerformance can be optimized(or you can always cut features…)Test, test, test - on a device!MIX 2011 – performance tool?