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ReadMeAboutSimpleNetworkStreams==================================1.2

SimpleNetworkStreamsshowshowtodosimplenetworkingusingtheNSStreamAPI.Thegoalofthissampleisverylimited:itdoesnotdemonstrateeverythingyouneedtoimplementafullyfledgednetworkingproduct(moreonthisbelow),rather,itfocusesonusingtheNSStreamAPItomovearealisticamountofdataacrossthenetwork.

SimpleNetworkStreamsrequiresiOS4.0orlater,althoughthecorenetworkingcodeshouldalsoworkoniPhoneOS2.xandMacOSX.

PackingList------------Thesamplecontainsthefollowingitems:

oReadMeAboutSimpleNetworkStreams.txt--Thisfile.oSimplifyingAssumptions.txt--Moredocumentation.oSimpleNetworkStreams.xcodeproj--AnXcodeprojectforthesample.oResources--Theprojectnib,images,andsoon.oAncillaryCode--Adirectoryfullofcodethat'snotdirectlyrelevanttothemainfunctionofthissample.oSendController.[hm]--Aviewcontrollerthatsendsfiles.

oReceiveController.[hm]--Aviewcontrollerthatreceivesfiles.oReceiveServerController.[hm]--Aviewcontrollerthatimplementsaservertoreceivefiles.oSendServerController.[hm]--Aviewcontrollerthatimplementsaservertosendfiles.

UsingtheSample----------------Youcantestthesamplewithonedevice(usingloopback),onesimulator(usingloopback),twodevices,twosimulators(ondifferentmachines),adeviceandasimulator,adeviceandtheMaccommandline,andasimulatorandtheMaccommandline.AlldevicesandsimulatorsmustbeonthesameWi-Finetwork.

TestingwiththeGUIissimple:

1.Runtheprogramononedevice(orsimulator).

2.Switchtothe"ReceiveServer"tabandtapStart.

IMPORTANT:Iftheserverfailstostartwiththemessage"Registrationfailed",it'slikelythatanothercopyoftheserverisrunningonthesamenetwork.Formoreinformationaboutthislimitation,see"SimplifyingAssumptions"below.

3.Switchtothe"SendServer"tabandtapStart.

4.Ifyou'reusinganotherdevice(orsimulator),runtheprogramonthat.

5.Switchtothe"Send"tabandtaponeoftheimagestosend.

6.Switchtothe"Receive"tabandtapReceivetoreceiveanimage.

IfyouwanttotestagainsttheMaccommandline,switchtotheInfotabforinstructions.

Theprogramhasfourbuilt-intestimageswithexponentiallyincreasingsize.Transferringthefirstimage,shownatthetopleft,willbeveryquick.Transfe

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rringthelastimage,shownatthebottomright,willbeveryslow(athousandtimesslower!).Thisallowsyoutotestvariousthingsthatyoucouldn'ttestotherwise,liketheStopandCancelbuttons.See-[AppDelegatepathForTestImage:]formoreinformationonhowtheselargeimagesarecreated.

BuildingtheSample-------------------ThesamplewasbuiltusingXcode3.2onMacOSX10.6withiPhoneSDK4.0.YoushouldbeabletojustopentheprojectandchooseBuildfromtheBuildmenu.TheresultingprogramshouldbecompatiblewithalldevicesrunningiOS4.0andlater,althoughthebulkofmytestingwasdonewithaniPhonetouch(secondgeneration)runningiOS4.0.

HowitWorks------------ThesampleisaverysimpleapplicationoftheNSStreamAPIfornetworking.Eachviewcontrollerisaself-containednetworkingexample.Theclientviewcontrollers(SendControllerandReceiveController)createanNSNetServiceforahard-codedBonjourservicename,thencreateanNSOutputStreamorNSInputStreamfromthatnetservice,thenschedulethatstreamforasynchronousoperations.Thebulkoftheinterestingcodeisinthe-_startSend/_startReceiveand-stream:handleEvent:methods.

Theserverviewcontrollers(ReceiveServerControllerandSendServerController)a

realittlemorecomplex.TheycreatealisteningTCPsocket,wrapthatsocketinaCFSocket,andthenregisteritwithBonjourusingNSNetService.Whenaconnectionarrives,theywraptheconnection'ssocketinanNSStreamandthenschedulethatstreamforasynchronousoperations.Thebulkoftheinterestingcodeisinthe-_startServer,_startSend/_startReceive,and-stream:handleEvent:methods.

SimplifyingAssumptions-----------------------TomakethissampleeasytounderstandImadeanumberofsimplifyingassumptions.Ifyou'recreatingarealapplication,youshouldreadthe"SimplifyingAssumptions.txt"documenttoseewhichoftheseassumptionsmightaffectyourapplication,andforpointersonhowtoturnthissamplecodeintoproduction-quality

code.

CreditsandVersionHistory---------------------------Ifyoufindanyproblemswiththissample,pleasefileabugagainstit.

1.0(May2009)wasthefirstshippingversion.

1.1(Sep2009)implementedsomecosmeticchangestobringitinlinewithother,similarsamples.

1.2(June2010)updatedforiOS4.0.

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AppleDeveloperTechnicalSupportCoreOS/Hardware

11Sep2009