飞信symbian客户端接口规范

Chapter19:MobileApplicationsObjectives•Defineamobileapplication.•Understandcomponentsfoundinamobileapplication.•Learnthekeyscenarioswheremobileapplicationswouldbeused.•Learnthedesignconsiderationsformobileapplications.•Identifyspecificscenariosformobileapplications,suchasdeployment,powerusage,andsynchronization.•Learnthekeypatternsandtechnologyconsiderationsfordesigningmobileapplications.目标定义个移动应。理解建立个移动应素。学习移动应重户场景。学习移动应设计考虑因素。鉴别特定移动应场景，如部署，电量同步等。学习移动应关键模型技术因素。OverviewAmobileapplicationwillnormallybestructuredasamulti-layeredapplicationconsistingofuserexperience,business,anddatalayers.Whendevelopingamobileapplication,youmaychoosetodevelopathinWeb-basedclientorarichclient.Ifyouarebuildingarichclient,thebusinessanddataserviceslayersarelikelytobelocatedonthedeviceitself.Ifyouarebuildingathinclient,thebusinessanddatalayerswillbelocatedontheserver.Figure1illustratescommonrichclientmobileapplicationarchitecturewithcomponentsgroupedbyareasofconcern.概述通常，移动应由个层应结构，包括户体验、业务数据等。移动应时，以选择做个基于网络瘦客户端或个富客户端。如果选择富客户端，那么业务数据服务层般位于设备本身。如果选择瘦客户端，那么业务数据层则位于服务器端。图1，根据组成素关系，描述个富客户端移动应架构。图1：常富客户端应架构DesignConsiderationsThefollowingdesignguidelinesprovideinformationaboutdifferentaspectsyoushouldconsiderwhendesigningamobileapplication.Followtheseguidelinestoensurethatyourapplicationmeetsyourrequirementsandperformsefficientlyinscenarioscommontomobileapplications:设计考虑当设计个移动应时，面设计方针提供应该考虑不同方面信息。遵循这些指能够确保应能够满足需求，同时，于般移动应能够有效。•Decideifyouwillbuildarichclient,athinWebclient,orrichInternetapplication(RIA).Ifyourapplicationrequireslocalprocessingandmustworkinanoccasionallyconnectedscenario,considerdesigningarichclient.Keepinmindthatarichclientapplicationwillconsumemoredeviceresourcesandwillbemorecomplextoinstallandmaintain.Ifyourapplicationcandependonserverprocessingandwillalwaysbefullyconnected,considerdesigningathinclient.Ifyourapplicationrequiresarichuserinterface(UI),onlylimitedaccesstolocalresources,andmustbeportabletootherplatforms,designanRIAclient.决定建立个富客户端、基于网络瘦客户端或富Internet应(RIA)。如果应需本地处理，偶尔联网必须工作，那么就考虑设计成个富客户端。记住，个富客户端应消耗更设备资源，按照维护工作比较责。如果应能够依靠服务器处理，并且直保持联网，那么就考虑设计瘦客户端。如果应需丰富户体验，使本地资源受限，并且必须能够移植其，那么就设计成RIA客户端。•Determinethedevicetypesyouwillsupport.Whenchoosingwhichdevicetypestosupport,considerscreensize,resolution(DPI),CPUperformancecharacteristics,memoryandstoragespace,anddevelopmenttoolenvironmentavailability.Inaddition,factorinuserrequirementsandorganizationalconstraints.决定支持设备类型。选择支持设备类型时，考虑屏幕、分辨率（DPI）、CPU特性、主存、扩展存储工具环境。另，还考虑户需求组织限制因素。•Designtheapplicationwithoccasionallyconnectedlimited-bandwidthscenariosinmind.Mostmobileapplicationsmustworkwhenanetworkconnectionisintermittentornotavailable.Itisvitalinthissituationtodesignyourcaching,statemanagement,anddataaccessmechanismswithintermittentnetworkconnectivityinmind.Batchcommunicationsfortimesofconnectivity.Choosehardwareandsoftwareprotocolsbasedonspeed,powerconsumption,and“chattiness,”andnotjustoneaseofprogramming设计偶尔联网，并且带宽受限应。数移动应必须间歇性地连接网络或网络不都能工作。这种间歇性网络连接，设计存、状态管理数据获机制重。有网络连接，就进行通信批处理。基于速度、功耗“繁琐”程度选择硬软协议，而并不从编程难易程度做。•DesignaUIappropriateformobiledevices,takingintoaccountplatformconstraints.Mobiledevicesrequireasimplerarchitecture,simplerUI,andotherspecificdesigndecisionsinordertoworkwithintheconstraintsimposedbythedevicehardware.KeeptheseconstraintsinmindanddesignspecificallyforthedeviceinsteadoftryingtoreusethearchitectureorUIfromadesktoporWebapplication.Themainconstraintsarememory,batterylife,abilitytoadapttodifferencescreensizesandorientations,security,andnetworkbandwidth.考虑约束，设计适合移动设备UI。移动设备需简单架构、简洁UI其特定设计满足设备硬所带资源受限。牢记这些限制设计适合设备程序，而非尝试着重桌面或网络应架构。最主限制包括存容量、电池寿命、适应不同屏幕分辨率能力、安全网络带宽。•Designalayeredarchitectureappropriateformobiledevicesthatimprovesreuseandmaintainability.Dependingontheapplicationtype,multiplelayersmaybelocatedonthedeviceitself.Usetheconceptoflayerstomaximizeseparationofconcerns,andtoimprovereuseandmaintainabilityforyourmobileapplication.However,aimtoachievethesmallestfootprintonthedevicebysimplifyingyourdesigncomparedtoadesktoporWebapplication.设计分层架构，适应移动设备，提重性维护性。基于应类型，不同层位于设备本身部。利层概念最化地分离考虑因素，并且提移动应重性维护性。但，桌面或网络应相比，通过简化设计实现这个最覆盖区。•Designconsideringdeviceresourceconstraintssuchasbatterylife,memorysize,andprocessorspeed.EverydesigndecisionshouldtakeintoaccountthelimitedCPU,memory,storagecapacity,andbatterylifeofmobiledevices.Batterylifeisusuallythemostlimitingfactorinmobiledevices.Backlighting,readingandwritingtomemory,wirelessconnections,specializedhardware,andprocessorspeedallhaveanimpactontheoverallpowerusage.Whentheamountofmemoryavailableislow,theMicrosoft®WindowsMobile®operatingsystemmayaskyourapplicationtoshutdownorsacrificecacheddata,slowingprogramexecution.Optimizeyourapplicationtominimizeitspowerandmemoryfootprintwhileconsideringperformanceduringthisprocess.考虑设备资源受限因素，如电池寿命、存处理器速度等。每个设计应该考虑移动设备CPU受限、存/存储容量电池寿命。般说，电池寿命移动设备最受限因素。背景灯、读存、无线连接、特殊硬处理器速度，所有这些总体功耗产生重影响。存少，Microsoft®WindowsMobile®操作系统提醒关闭应程序或丢失缓存数据、降程序执行速度等等。考虑性能表现，优化应程序，功耗存使降最。MobileClientFrameThereareseveralcommonissuesthatyoumustconsiderasyourdevelopyourdesign.Theseissuescanbecategor