Software Architectur - 天津大学计算机科学与技术学.ppt

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1、SoftwareArchitectureChapter2:ArchitecturalPatternsFengZhiyongTianjinUniversityApr.5,2007InteractiveSystemsTheModel-View-Controllerpattern(MVC)dividesaninteractiveapplicationintothreecomponents.Themodelcontainsthecorefunctionalityanddata.Viewsdisplayinformationtotheuser.Controllersh

2、andleuserinput.Viewsandcontrollerstogethercomprisetheuserinterface.Achange-propagationmechanismensuresconsistencybetweentheuserinterfaceandthemodel.ThePresentation-Abstraction-Controlpattern(PAC)definesastructureforinteractivesoftwaresystemsintheformofahierarchyofcooperatingagents.E

3、veryagentisresponsibleforaspecificaspectoftheapplication'sfunctionalityandconsistsofthreecomponents:presentation,abstraction,andcontrol.Thissubdivisionseparatesthehuman-computerinteractionaspectsoftheagentfromitsfunctionalcoreanditscommunicationwithotheragents.Model-View-ControllerT

4、heModel-View-Controllerarchitecturalpattern(MVC)dividesaninteractiveapplicationintothreecomponents.Themodelcontainsthecorefunctionalityanddata.Viewsdisplayinformationtotheuser.Controllershandleuserinput.Viewsandcontrollerstogethercomprisetheuserinterface.Achange-propagationmechanism

5、ensuresconsistencybetweentheuserinterfaceandthemodel.ExampleContext:Interactiveapplicationswithaflexiblehuman-computerinterface.ProblemThesameinformationispresenteddifferentlyindifferentwindows,forexample,inabarorpiechart.Thedisplayandbehavioroftheapplicationmustreflectdatamanipulat

6、ionsimmediately.Changestotheuserinterfaceshouldbeeasy,andevenpossibleatrun-time.Supportingdifferent'lookandfeel'standardsorportingtheuserinterfaceshouldnotaffectcodeinthecoreoftheapplication.SolutionMVCdividesaninteractiveapplicationintothethreeareas:processing,output,andinput.Themo

7、delcomponentencapsulatescoredataandfunctionality.Themodelisindependentofspecificoutputrepresentationsorinputbehavior.Viewcomponentsdisplayinformationtotheuser.Aviewobtainsthedatafromthemodel.Therecanbemultipleviewsofthemodel.Eachviewhasanassociatedcontrollercomponent.Controllersrece

8、iveinput,usuallyase