NET core 2 0 by example

.NETCore2.0ByExample






LearntoprograminC#and.NETCorebybuildingaseriesofpractical,crossplatformprojects











RishabhVerma
NehaShrivastava

BIRMINGHAM-MUMBAI



.NETCore2.0ByExample
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Contributors


Abouttheauthors
RishabhVermaisaMicrosoftcertifiedprofessionalandworksatMicrosoftasadevelopment
consultant,helpingtodesign,develop,anddeployenterprise-levelapplications.Hehas10years'
hardcoredevelopmentexperienceonthe.NETtechnologystack.Heispassionateaboutcreating
tools,VisualStudioextensions,andutilitiestoincreasedeveloperproductivity.Hisinterestsare
.NETCompilerPlatform(Roslyn),VisualStudioExtensibility,andcodegeneration.
Nowordscandescribemygratitudetomyparents,ShriRakeshChandraVermaandSmt.
PratibhaVerma,whosupportedmeduringthewritingofthisbook.Theirhardworkoverthe
yearshasbeentheinspirationbehindmetakingupthischallengingwork.Iwouldalsoliketo
offerspecialthankstomybrother,ShriRishiVerma,whokeptmotivatingmedayinanddayout.
Ialsowanttothankmycolleagues,managers,andteamatMicrosoftfortheirsupport.

NehaShrivastavaisaMicrosoftcertifiedprofessionalandworksasasoftwareengineerforthe
WindowsDevicesGroupatMicrosoftIndiaDevelopmentCenter.Shehas7years'development
experienceandhasexpertiseinthefinancial,healthcare,ande-commercedomains.NehadidaBE
inelectronicsengineering.HerinterestsaretheASP.NETstack,Azure,andcross-platform
development.Sheispassionateaboutlearningnewtechnologiesandkeepsherselfuptodatewith
thelatestadvancements.
Iwouldliketothankmyparents,ShriO.P.ShrivastavaandSmt.ArchanaShrivastava,fortheir
continuoussupportandmotivation.Their"NeverSayDie"mantrakeepsmeupandrunning.
Heartfeltthankstomybrother,Dr.UtkarshShrivastava,mysister-in-law,Dr.Samvartika

Shrivastava,andmylittleangelSarvagya,fortheircontinuoussupportandwordsof
encouragement.Thisbookwouldn'thavebeenpossiblewithouttheblessingsofmybeloved
Dadi!


Aboutthereviewer
PavolRovenskyisasoftwaredeveloperlivingintheUK.OriginallyfromSlovakia,heearneda
degreeinradioelectronicsfromCzechTechnicalUniversityandstudiedmedicinefromthe
CharlesUniversityinPrague.
HehasworkedintheCzechRepublic,Iceland,Switzerland,andtheUK,mostlydeveloping
softwareforthebiotech/pharmasectorandcontractinginvarioussoftwarecompanies,hehas
professionalexperiencespanning25years.
Hehasworkedwithvarioustechnologies,includingC++,Java,PowerBuilder,C#,WiXToolset,
.NETFramework,ORMs.
HisinterestinaccountingandbusinessmanagementledhimtodevelopProudNumbers,whichisa
reportingtoolformanagementaccountants.
Iwouldliketothankmywife,Jana,anddaughter,Emma,fortheirpatienceandencouragement.







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Preface
InthisevergrowingworldofIT,wehavenumerousdifferentplatforms,frameworks,and
languagesonwhichapplicationsarebuiltbasedonthebusinessneeds,requirements,andthe
developer'sinterest.Toremovethisbarrierofdifferentplatforms,Microsoftcameupwiththe
fastest,latest,andgreatestversionof.NET,the.NETCorecross-platformopensourceframework.
Usingthisframework,beginner-leveldeveloperscanworkondifferentplatforms,andexperienced
developersandarchitectscanconsumetheirAPIsandlibrariesacrossdifferentplatforms.This
bookcoverssimpleexamplesofusing.NETCoretobuildmodern,internet-connected,andcloudbasedapplications.Thebookwillhelpusdevelopsimpleyetinterestingapplicationstoprovide
thereaderswithworkingcodeexamples.WewilldevelopaTic-Tac-Toegametobeginwith,then
buildareal-timechatapplication,LetsChat(forchattingwithouronlineFacebookbuddies),a
samplechatbot,andadummymoviebookingapplication.


Whothisbookisfor
Thisbookisfordevelopersandarchitectswhowanttolearnhowtobuildcross-platformsolutions
usingMicrosoft.NETCore.Itisassumedthatyouhavesomeknowledgeofthe.NETFramework,
OOP,andC#(orasimilarprogramminglanguage).Thisbookisalsousefulfordeveloperswho
wanttodevelopacross-platformapplicationthatsupportsalreadyexistinglibrariesorlibraries
thattheyhavecreatedondifferentplatforms.Thebookcoversawidebreadthoftopicsand
attemptstoexplainallthefundamentalsneededtobuilda.NETCoreapp.Thebookalso
introducesyoutoSignalRCore,EntityFrameworkCore,containers,F#functionalprogramming,
andtipsandtricksfordevelopingon.NETCore.


Whatthisbookcovers
,GettingStarted,discussesalltheprerequisitesrequiredforalltheexamplesinthisbook,
forexample,settingupanUbuntuVMusingVirtualBoxandthroughHyper-VonWindows,and
installing.NETCore2.0andtools.WewillalsobeintroducedtoF#anditsfeaturesinbrief,see
howF#isdifferentfromotherobject-orientedprogramminglanguages,andlookatthedifferences

betweenC#andF#.WewillalsocreateasimplesampleapplicationusingF#,inordertoget
familiarwiththeF#syntax.
Chapter1

,NativeLibrariesin.NETCore,demonstrateswhatthencurseslibraryisandhowto
extendtheconsolecapabilitiesof.NETCorebyimplementingthencursesnativelibraryonLinux,
andalsohowtointeroperatewithexistingnativeandMonolibraries.Wewillbuildasample
nativelibraryandapplicationthatimplementsthisnewsamplelibrary.
Chapter2

,BuildingOurFirst.NETCoreGame–Tic-Tac-Toe,illustrates.NETCoreusingan
examplegameapp,Tic-Tac-Toe.WewillbeintroducedtoSignalRCoreandlearnhowitcanbe
usedtodevelopareal-timewebapplication.InsteadofusingamonochromaticXandO,players
canusetheirimagestoplaythegame.Withthisexamplegameapp,wewillgetanoverviewofthe
code(classes,interfaces,models,andsoon)andwilllearnaboutcompiling,building,andtesting
theapplication,whichappliesto.NETCoreingeneral.
Chapter3

,Let'sChatWebApplication,introduceswebdevelopmentwithASP.NETCore.Thisis
donethroughasimplechatapplication,Let'sChat,onWindows.Wealsocoverprojectsetup,
applicationarchitectureanditsdescription,SignalRCore,DependencyInjection,configuration,
logging,andmore.WewillalsogetfamiliarwiththefundamentalsofthefeaturesofASP.NET
Core,whichareintroducedwhiledevelopingthecomponentsoftheapplication.
Chapter4

,DevelopingtheLet'sChatWebApplication,demonstratesnumerousexamplesandcode
snippetsinordertofundamentalsandfeaturesofASP.NETCore.Bytheendofthischapter,the
Let'sChatapplicationwillbereadyforuse.Wewillalsogetacquaintedwithtesting,hosting,
security,andtheperformanceaspectsofwebdevelopment.
Chapter5

,TestingandDeploying–TheLet'sChatWebApplication,explainsthe.NETCore
deploymentmodel.WewilldeploytheLet'sChatapplication.WewillbeintroducedtoDocker
containers.WewillalsodevelopanddeployaASP.NETCore-basedchatbotandintegrateitwith
theLet'sChatapplication.
Chapter6

,TotheCloud,teachesyouwhatthecloudisandwhythemodern-daydevelopershouldbe
conversantwithcloudtechnologies.WewillgetstartedwithAzure,andmakeourselvesawareof
theAzuremanagementportal.WewilllearntocreateaVMfromtheportalandseethatitis
automatedusingPowerShellorotherlanguagesusingtheAzureSDK.WewillthenmanagetheVM
Chapter7


usingPowerShellandseehowtostartandstopit.Wewillalsolearnhowtocreateawebappin
AzurefromVisualStudio2017itselfandlearnhowtopublishprofiles.Finally,wewillhavean
overviewofAppServices,andtakeaquicklookatAzurestorage.
,MovieBookingWebApp,discussesEntityFramework(EF)andEntityFramework
Core.Wewilllearnaboutthefeaturesofanddifferencesbetweenthetwo.Wewillalsolearnthat
weshoulduseEFCoreonlyifEFcannotbeusedorthereisapressingcross-platformrequirement
touseEFCore.WewilllearnhowtoperformCRUDoperationsusingEFCorebycreatinga
simpleapp.Wewillthendevelopasimplemoviebookingappandlearnhowtodeployitusing
VisualStudio.WewillalsoseehowwecanmonitorourwebappbyenablingApplication
Insights.
Chapter8

,Microserviceswith.NETCore,givesanoverviewofthemicroservicearchitectureand
howitisanextensionofSOAandovercomesthelimitationsoftraditionalmonolithicapps.We
willlearnabouttheimportantarchitecturaldifferencesbetweenASP.NETandASP.NETCore.We
willlookattipstokeepinmindwhiledevelopingASP.NETCore2.0applications,duetothe

architecturaldifferences.Wewillthendiscusshandyinformation,steps,andtipstoimprovethe
performanceofASP.NETCoreapps,afewtipsonAzureaswell,andthenanewexperimental
projectoftheASP.NETCoreteam,whichiscalledBlazor.We'llwrapupthechapterwitha
discussiononthe.NETCore2.1roadmapandthefeaturesexpectedinthisnewversion.
Chapter9

,FunctionalProgrammingwithF#,discussesfunctionalprogramminganditsfeatures,
suchashigher-orderfunctions,purity,lazyevaluation,andcurrying.WewilllearnaboutF#basics,
suchasclasses,letanddobindings,generictypeparameters,propertiesinF#,howtowrite
functionsandlambdaexpressionsinF#,andexceptionhandling.Also,we'lllookatdifferenttypes
ofdataprovidersinF#andhowdifferenttypesofdataparserwork.Wewillalsolearnabout
queryingSQLServervNextwithF#.
Chapter10


Togetthemostoutofthisbook
Thisbookisaimedatexperienceddeveloperswhousedifferentplatforms—Windows,Linux,
Ubuntu,macOS—andwanttotryMicrosoft.NETCore2.0crossplatform.DevelopersusingC#,
C,orC++fordevelopmentwhoareinterestedinextendingtheirknowledgeoffunctional
programming,beginnerswhowanttounderstandF#andfunctionalprogramming,weassumethat
youhaveabasicunderstandingofC#andareawareofthe.NETframeworkandWindows.


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GettingStarted
Inthischapter,wearegoingtolearnabouttoolsusedtoperformdevelopmenttasksfor.NETCore
2.0onWindowsandLinuxoperatingsystems.Also,wewilllearnhowtosetupLinuxand
virtualizationusingVirtualBoxandHyper-V.Thischapterwillcoverhowtoinstall.NETCore2.0
andtoolsforWindowsandLinux(Ubuntu).Wewilllearnaboutthevirtualmachine(VM)setup
forUbuntuandcreateyourfirstsimple.NETCore2.0runningapplicationcode.Wewillconfigure
theVMtomanageyourfirstapplication.Thepurposeofthischapteristogetageneralideaofthe
requiredtoolsandhowtoinstall.NETcore2.0SDKforWindowsandLinux,andgiveyoubasic

F#understanding.
Thischapterwillcoverthefollowing:
DownloadingtherequiredtoolsforWindowsandLinux
Installing.NETCore2.0andtools(Windows)
SettingupanUbuntuLinuxVM
Installing.NETCore2.0andtools(Linux)
Creatingsimplerunningcode
F#primer


DownloadingrequiredtoolsforWindows
andLinux
Inthissection,wewilldiscusstheprerequisitestobedownloadedforbothWindowsandLinux
operatingsystemstostartdevelopmentwith.NETCore2.0.WewillstartwithWindowsandthen
movetoLinux.