Funda Okuyisisekelo kwe-Android App Programmieren

Uma ufuna indlela yokufunda ukuthi ungaluhlela kanjani uhlelo lwe-Android, lapho-ke kufanele ucabange ukuthatha isifundo se-Android Apps Programmieren. Lezi zifundo ziphelele kwabaqalayo, njengoba zingadingi ulwazi lwangaphambili noma isizinda. Uzofunda iJava, Kotlin, Hudula-uwisa, kanye Nezinjongo. Ngemva kokuqeda lesi sifundo, uzoba nokuqonda okuphelele kwezinhlelo ze-Android. Nokho, kufanele wazi amanye amaphuzu abalulekile ngaphambi kokuqala lesi sifundo.

Java

Uma ungathanda ukufunda izisekelo zohlelo lokusebenza lwe-Android ku-Java, uzodinga ulwazi oluhle lolimi. I-Java iwulimi lokuhlela olusetshenziswa kakhulu ku-Android futhi iwulimi oluncanyelwayo lokudala izinhlelo zokusebenza zeselula. Lesi sifundo sihlanganisa izisekelo ze-Java futhi sethula i-Object-Oriented Programming. Uzofunda futhi ukuthi usebenza kanjani ngesitudiyo se-Android, ithuluzi lokuthuthukisa uhlelo lokusebenza elidumile. Phakathi nesifundo, uzodala iphrojekthi ye-Android futhi uhlole izisekelo zokudala uhlelo lokusebenza lwe-Android.

Ngenkathi izindlela ezimisiwe zohlelo lokusebenza lwe-Android ku-Java zidumile, futhi balinganisela kakhulu emandleni abo. Nakuba le ndlela iphumelela ekudaleni izinhlelo zokusebenza ezilula ze-Android, kuzodingeka ushintshe ikhodi ye-Java uma ufuna ukwengeza izici ezengeziwe. Uzodinga ukufunda i-Java kahle, futhi akusiwona wonke umuntu. Osomabhizinisi abaningi bakhetha ukuqasha umthuthukisi wohlelo lokusebenza lwe-Android okhethekile ukuthi asebenze ezinhlelweni zabo zokusebenza.

Uma ungumfundi othuthukile we-Android, ungasebenzisa i-Async-Task-Framework futhi usebenzise Izinhloso ukuze unikeze imisebenzi. Ungasebenzisa futhi isistimu yokungena eyakhelwe ngaphakathi ye-Android Studio ukuze wenze uhlelo lwakho lokusebenza lwe-Android lungabi namaphutha. Futhi uzojabula ukuthi ukwenzile uma izinhlelo zakho zokusebenza zisebenza njengoba bezihlosiwe. Vele uqiniseke ukuthi uhlola isistimu yokugawula ngaphambi kokuwahambisa emakethe yohlelo lokusebenza.

Kotlin

Uma uzama ukubhala uhlelo lokusebenza lwe-Android, ungase ucabange ngokusebenzisa i-Kotlin. Lolu limi olusha lokuhlela lwezinhlelo zokusebenza ze-Android luyinketho enhle ngenxa yobulula balo. Ukuba lula kwayo kuyisici esibalulekile okufanele usikhumbule, njengoba ukufunda Kotlin kungaba nzima. Nokho, uma usuwazi kahle izisekelo ze-Java, uzothanda ukusebenza noKotlin. Akukhona nje ukuthi kwenza ukuphila kwakho kube lula, kodwa futhi iphephile futhi i-agnostic yesikhulumi.

Uhlelo lokusebenza lwe-Android luqukethe uchungechunge lwemisebenzi, eyodwa kwesikrini ngasinye. Ngemva kokuqeda umsebenzi owodwa, udlulela kwesilandelayo. Umsebenzi oyinhloko kuhlelo lokusebenza i-MainActivity, okuyisigaba se-Java kanye nesigaba esingaphansi sesigaba se-Android Umsebenzi kanye ne-AppCompatActivity. Yindawo yokungena yohlelo lokusebenza futhi iqukethe izindlela ezimile eziyinhloko() futhi onDala().

Ngemva kokufunda izisekelo ze-Kotlin, kufanele ucabangele ukufunda indlela yokuthuthukisa uhlelo lokusebenza lwe-Android ulusebenzisa. Ziningi izinsiza ezitholakalayo zokufunda indlela yokusebenzisa i-Kotlin ye-Android, futhi ungakwazi ukulandela kanye nephrojekthi. Isifundo samahhala esisebenzisa indlela esekwe kuphrojekthi sikusiza ukuthi uthuthukise amakhono akho e-Kotlin. Ukuze ufunde kabanzi, hlola izifundo ezinikezwa yi-Google noma i-Udacity.

Hudula-uwisa

Ukuze usebenzise ukudonsa nokuwisa kuhlelo lwakho lokusebenza lwe-Android, udinga ukwazi imininingwane yokuthi indlela yokudonsa nokuwisa isebenza kanjani. Imicimbi yokudonsa bese uwisa ingaqaliswa inoma iyiphi idivayisi ngokucupha isicuphi somsebenzisi, kanye nohlaka lwe-Android luhlinzeka ngekilasi lomcimbi wokuhudula nokuhudula abalaleli ngesenzo ngasinye. Inqubo yokudonsa ilula kakhulu: uhlelo lokusebenza lomthombo lucupha umcimbi wokuhudula ngokuthumela i-startDrag() callback ohlelweni. Lokhu kuphinda kushayelwe futhi kunikeze idatha yokuhudula ohlelweni. Ngemva kokuphatha ukudonsa, uhlelo lokusebenza lomthombo lungashayela umcimbi wokwehlisa ukuze uhlole ukuthi uphumelele yini.

Uhlaka lwe-Android lokudonsa nokuwisa luvumela abasebenzisi ukuhambisa idatha phakathi kwezinto eziningi ngesakhiwo somsebenzi. Ikilasi lomcimbi wokuhudula, abalaleli, futhi amakilasi aklanyelwe ukusekela ukuhanjiswa kwedatha. Ungasebenzisa futhi uhlaka lokuhudula ukwenza ezinye izenzo ze-UI. Ngaphezu kokuhambisa idatha phakathi kwezinto, ingasetshenziswa futhi ukudala ukuzulazula okusebenzisanayo nezinye izici. Nokho, ngezici ezithuthukile, kufanele ucabangele ukusebenzisa ukudonsa nokuwisa kuhlelo lwakho lokusebenza kuqala.

Kufanele ubhalise njengomlaleli ukuze uhudule imicimbi. Imicimbi yokuhudula icushwa noma nini lapho umsebenzisi enyakaza noma ekhulula into ethi Buka. Umcimbi wokuhudula uthunyelwa kubalaleli nezindlela zokuphinda ushayele. Lezi zindlela zithola idatha bese zinquma ukuthi ziyamukele noma ziyenqaba. Ungasebenzisa lezi zindlela ukushintsha ukubukeka kwento ethi Buka. Uma usulungele ukudala uhlelo lokusebenza olunezici zokudonsa nokuwisa, kufanele ujwayelane nezisekelo zokudonsa nokuwisa uhlelo lokusebenza lwe-Android.

Izinhloso

Izinhloso zisetshenziselwa ukusuka komunye umsebenzi ukuya komunye ohlelweni lokusebenza lwe-Android. Izinhloso zikuvumela ukuthi usuke komunye umsebenzi uye komunye ngokusebenzisa ulimi oluthile. Ngokuphambene nezinhlelo zokusebenza ze-PC ezivamile, ezinesikrini esisodwa kuphela, Izinhlelo zokusebenza ze-Android zingaba nenqwaba yamakhasi esikrini, ngayinye inikezelwe kumsebenzi othile. Lawa makhasi esikrini afinyelelwa ngumsebenzisi kumsebenzi oqondiwe. Izinhloso zikusiza ukuthi wakhe izinhlelo zokusebenza zeselula ezingcono.

Izinhloso zingasetshenziswa futhi ukweqa kusuka kuhlelo lokusebenza kuya kuhlelo lokusebenza. Abasebenzisi abaningi be-Android babona begxuma besuka kolunye uhlelo baye kolunye. Ngokwesibonelo, uma umsebenzisi ethola isixhumanisi sokukhokha, bangase bavule isicelo se-PayPal noma se-GPay. Ezimweni ezinjalo, isistimu ingaphendula ngokudlulisela Inhloso kumsebenzisi. Izinhloso zikuvumela ukuthi usuke kuhlelo lokusebenza olulodwa uye kolunye kalula. Ungakwazi ngisho nokuwasebenzisa ukuze udale uhlelo olusha ngokuphelele!

Izinhloso zisebenza ngendlela ehlukile esimweni ngasinye. Uma ufuna ukubonisa ulwazi mayelana nezintengo zesitoko, ungasebenzisa umsebenzi ongavumelanisi obizwa ngokuthi “ListView”. Lolu hlelo lokusebenza lubonisa idatha ekubukeni kohlu lapho umsebenzisi achofoza engxenyeni yokulalela. Okufanayo kuya ekufakeni kuhlu ulwazi lwezezimali kuhlelo lokusebenza. Ngaphezu kwalokho, ungasebenzisa imisebenzi ye-asynchronous ngezenzo eziyinkimbinkimbi, njengokungena ku-inthanethi noma ukuhlola i-imeyili yakho.

Ibhokisi lesihlabathi

Enye yezindlela ezinhle kakhulu zokuvikela uhlelo lwe-Android ukusebenzisa i-sandboxing. Le nqubo ivikela isistimu yokusebenza ezinhlelweni ezinonya ngokuqalisa uhlelo lokusebenza ngokwalo “isikhala.” Lokhu kuvikela idivayisi yomsebenzisi kumthelela wezinye izinhlelo zokusebenza. Ukusebenzisa i-sandboxing kulula kakhulu futhi kuzokwenza uhlelo lwakho lokusebenza lwe-Android luphephe kubasebenzisi bakho. Ukuze ufunde ukusebenzisa i-sandboxing kuhlelo lokusebenza lwe-Android, funda uqhubeke.

Ngokwesibonelo, ake sithi ufuna ukubonisa amasheya wabasebenzisi bakho. Khona-ke, ungasebenzisa i-BufferedReader kanye ne-InputStream ukuze ufunde idatha. Ukusebenzisa i-InputStream, ungasebenzisa idatha yezezimali efanisiwe ukuze ubonise okuqukethwe komlayezo welogi. Ungasebenzisa lolu chungechunge olufanayo ukuze ubonise umlayezo kubasebenzisi. Lapho usebenzisa i-inthanethi, uhlelo lwe-Android ludinga umsebenzi ongavumelanisiwe. Lokhu kubizwa nge-HoleDatenTask, futhi igijima ngemuva.

I-sandbox ye-Android isebenzisa i-ID yomsebenzisi ukuze iqinisekise ukuvikeleka phakathi kwezinhlelo zokusebenza nezinqubo. Imodeli yayo yokuphepha iphoqelela ukuhlukaniswa kwezinqubo nabasebenzisi. Iphinde ilawule ukufinyelela kumafayela angahlobene nohlelo lokusebenza. Lokhu kuvikela idivayisi ezinhlelweni ezingalungile. Ibhokisi lesihlabathi lilula, ezifundekayo, futhi isekelwe ekuhlukaniseni komsebenzisi wesitayela se-UNIX kwezinqubo. Iphinde isebenzise izimvume zefayela. Kafushane, igcina isistimu ye-Android iphephile ezinhlelweni ezinonya.

Java programming

Uma umusha ohlelweni lwe-Android, ungase uzibuze ukuthi ungaqala ngaphi. Ngenhlanhla, kunezinsiza ezimbalwa ezitholakalayo zokukusiza ukuthi uqalise. Ukusebenzisa ithuluzi lokuthuthukisa i-Android njenge-Android Studio kungenye yezindlela ezilula zokuqalisa. Kumahhala futhi, ngakho-ke asikho isizathu sokulinda uze ube uchwepheshe ukuze uqalise! Lesi sifundo sizokufundisa izisekelo ze-Java kanye nohlelo lwe-Android. Ihlanganisa futhi indlela yokudala uhlelo lokusebenza nokudala igeyimu.

Isifundo sokuqala sohlelo lwe-Android siqala ngesingeniso se-Hole Data Button kanye Nento Yomlaleli., enesibopho sokuhlonza okokufaka komsebenzisi. Bese ihlanganisa amakilasi angaziwa kanye nokwelashwa kwemicimbi. Ngaphezu kwalokho, abafundi bazofunda mayelana namalungiselelo e-Quellcode, ithuluzi lohlelo lwe-Java le-Android. Lawa mathuluzi akwenza kube lula ukudala Izinto Zomlaleli futhi athuthukise ukubonakala kwekhodi yakho.

Uma ungunjiniyela ofuna ukuthuthukisa uhlelo lokusebenza lwe-Android, I-Java iyingxenye ebalulekile yenqubo. Ukwakha uhlelo lokusebenza lwendabuko lwe-Android nge-JavaScript kudinga i-SDK, njenge-Android Studio. Ngokungafani nezinhlelo zokusebenza zewebhu, Izinhlelo zokusebenza zomdabu ze-Android zingafinyelela ngokuqondile kuzo zonke izingxenyekazi zekhompuyutha zeselula nesofthiwe, okuhlanganisa ikhamera nemakrofoni. Ngenxa yalokhu, uma ungumthuthukisi, uzoba nethuba ngaphezu konjiniyela abasebenzisa i-iOS noma iWindows.

Ikhodi ye-Java yezinhlelo zokusebenza ze-Android

Nakuba kungenzeka ukudala izinhlelo zokusebenza ze-Android usebenzisa ezinye izilimi, I-Java ulimi olusemthethweni lokuhlela lwenkundla. Nakuba zikhona ezinye izilimi zokuhlela, abaholi abaningi bamabhizinisi bashintshela e-Kotlin ukuze babhale izicelo zabo. Twitter, I-Pinterest, I-Uber, kanye ne-AirBnB bonke benza ushintsho ukuze basebenzise i-Kotlin. Ungafunda kabanzi ngakho ngokufunda umhlahlandlela wethu ophelele we-Kotlin-How-to.

Izinzuzo zokusebenzisa i-Java ukuze udale izinhlelo zokusebenza ze-Android ziningi. Kulula ukufunda ulimi, kulula ukulungisa iphutha, futhi uhlanganise, futhi igxile entweni, ukuvumela abathuthukisi ukuthi babhale izinhlelo zemojuli ezisebenzisa kabusha ikhodi. Ukwengeza, I-Java iyi-cross-platform, okwenza kube lula ukuhambisa ikhodi phakathi kwamasistimu ekhompyutha. Ngaphezu kwalokho, I-Java isebenzisana kakhulu nekhithi yokuthuthukisa ye-Android, okwenza kube ukukhetha okuhle kwamaphrojekthi ahlukahlukene.

Uma udala izinhlelo zokusebenza ze-Android, kubalulekile ukwazi ukuthi izithameli zakho ezihlosiwe ziyini nokuthi zilindeleni kuhlelo lokusebenza. Uma izethameli zakho ezihlosiwe zisencane, ungasebenzisa ulimi lwe-C++. Nokho, kufanele ukhumbule ukuthi i-C++ ayisebenziseki kalula njenge-Java, ngakho-ke ungase uthande ukucabangela olunye ulimi lokuhlela. Noma kunjalo, kufanele ukhethe ulimi olujabulisa izethameli zakho. Uma ungayazi i-Java, ungazama i-Objective-C. Lolu wulimi lokuhlela olugxile entweni enhloso ejwayelekile olwadalwa u-Tom Love no-Brad Cox kumasistimu e-Smalltalk-80..