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This slides describes about how to create a Windows Phone application with MVVM design pattern.
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/* Life runs on code */
UNDERSTANDING THE MODEL-VIEW-VIEWMODEL
PATTERNKamalakannan AnnamalaiSenior Software Engineer
Ilink-Systemshttp://kamalakannana.wordpress.com
WHAT IS MVVM?
• A weird acronym– Model – View – ViewModel
• Woven into WPF/SL/WP• Some confusion:– MVVM is really just the pattern– The rest are helpers, practices, etc.
• Why does MVVM pattern is best for WPF/SL/WP?
-WPF/SL/WP Controls are developed using MVVM internally.
THE MVC PATTERN
Model View
Controller
THE PASSIVE VIEW PATTERN
Model View
Controller
THE PRESENTATION MODEL PATTERN
Model View
Presentation Model
(ViewModel)
DataBinding
BLENDABILITY
• Testability, Maintainability, Blendability
• “The ability to be edited in Blend”
– (and Visual Studio designer…)
• Differentiate code in design and runtime
• Create design time data
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BRIDGING THE GAP
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View
ViewModel
DataBinding Commands Messages
Model
BRIDGING THE GAP
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View
ViewModelView
ViewModel
View
ViewModel
DEMO
© 2010 IdentityMine Inc. All Rights Reserved. 10Page:
Hello MVVM(and Hi Blend)
COMMANDS
• “Point of entry” for a method• Can be data bound• ICommand interface–Execute method–CanExecute method–CanExecuteChanged event
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FLAWS OF MVVM
• Too much code needed– INotifyPropertyChanged–Commands
• Some operations are tricky (set focus…)
• Not applicable to ASP.NET, etc• Message to community is not clear
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DEBUNK THE MYTHS
• “No code in the code behind”– “If you put code in the View's code-behind, the
MVVM police will take your family away”– “No need for converters”
• “MVVM is suitable for big projects”• “MVVM costs performance”• “MVVM is complex / makes my head
hurt”
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DEBUNK THE MYTHS
• “I don’t need separation because I don’t have a designer”
• “You cannot use MVVM with other patterns”
• “MVVM will make you rich and attractive”
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MVVM LIGHT TOOLKIT
• “Breaking the monotony”• http://www.galasoft.ch/mvvm/getstar
ted• http://mvvmlight.codeplex.com• Keep it small• Keep it simple
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MVVM LIGHT TOOLS
• Project templates (VS + Blend)• Item templates (VS + Blend)• Code snippets
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THANKS!/* Life runs on code
*/
