Uyenza njani iApps zeAndroid ngeKotlin

Ukuba awuzange wenze isicelo Android ngaphambili, unokoyikiswa kancinci ngawo onke amanyathelo abandakanyekayo. Ukuba ungumqali, unokuziva usoyika yi-Android Studio, enokuba nzima kancinane ukuyisebenzisa. Ngokuziqhelanisa kancinci, unokukhawuleza ukhululeke nge-Android Studio kunye neempawu zayo ezahlukeneyo.

Uphuhliso losetyenziso lwe-Android

Xa uphuhlisa usetyenziso lweselula, kubalulekile ukuqwalasela ukuba loluphi uhlobo lokusebenza oluya kulufuna imveliso yakho. Unokukhetha kwii-apps zomthonyama okanye ezixubileyo. Ii-apps zomthonyama zilungiselelwe iinkqubo ezithile zokusebenza, ngelixa ii-apps ezixubileyo zisebenza kwisikhangeli sewebhu. Ii-apps zomthonyama zintsonkothe ​​ngakumbi kwaye zifuna ulwimi lwenkqubo olwahlukileyo. Iiapps zeHybride zineemfuno zokusebenza ezifanayo, kodwa zitshiphu ukuphuhlisa.

Inkqubo yokuphuhlisa i-app inokubiza, kodwa kunokuba luncedo ukuba yenziwe ngokufanelekileyo. Iqala ngocwangciso olululo, ukuqokelelwa kweemfuno, kunye neeprototypes. Usetyenziso oluyimpumelelo lunokukunceda uphucule ishishini lakho kwaye ubandakanye abathengi. Ukuze uphuhlise usetyenziso oluyimpumelelo, kufuneka uyazi imarike yakho kwaye yintoni eya kubenza bonwabe.

I-Android yinkqubo yeselula ethandwayo. Kuyenzeka ukuba wenze usetyenziso oluxubileyo kunye nemveli ye-Android. Iiapps zomthonyama ziyilelwe ngokukodwa i-Android kunye nokufikelela kwihardware. Ukuba ufuna ukuphuhlisa i-app kwamanye amaqonga, Kuya kufuneka uyibhale kwakhona kwaye uyigcine ngokwahlukeneyo. Unokusebenzisa ukuthengwa kwe-app ukwenza imali.

Ukuba uceba ukwakha i-app ye-Android, qiniseka ukuba ukhetha inkampani exhasa inkqubo. Iinkampani ezifana nezitudiyo zoyilo zezeroseven zinamava ekuphuhliseni usetyenziso lwemveli kwaye zinokukunceda ukuba ukhuphe usetyenziso lwakho emhlabeni. Basebenzisa itekhnoloji yamva nje yedijithali ukwenza ii -apps ezihambelana nabathengi babo’ iimpawu, abaphulaphuli, kunye neemfuno.

Kotlin

Unomdla wokufunda ukwenza ii-apps ze-Android ngolwimi lweprogram ye-Kotlin. Kodwa ngaphambi kokuba uqale ukwenza ii -apps eKotlin, kufuneka uziqhelanise neziseko zeprogram ye-Android. Okwangoku, iibrendi ezininzi ezisekiweyo kunye nabaphuhlisi be-Android abanamava basebenzisa i-Kotlin. Nangona kunjalo, olu lwimi lutsha luneengxaki ezithile.

Umakhi oyintloko ufakwe kwisihloko seklasi. Oku kuphelisa imfuno yomakhi wesibini kunye neetters kunye neesethi. Ukongeza, awudingi parameters zomakhi. Kunoko, kufuneka ubhale kuphela iheader yeklasi yomgca omnye kunye nomakhi wakho oyintloko.

Ukuba ujonge enye indlela yeJava, ungafuna ukujonga kwi-Kotlin yendalo ye-Android app. Yeyanamhlanje, Ulwimi lodweliso oluchwetheziweyo olusebenza kuMatshini weJava obonakalayo (JVM). I-Kotlin ixhaswa ngokusemthethweni kwii-apps ze-Android. Awudingi nawaphi na amava angaphambili kwiJava okanye eKotlin, nangona ilungile kwabo banamava amancinci kwindawo yophuhliso lwesicelo.

Enye yezinto ezikhangayo kakhulu zeKotlin yinto elula. Ngenxa yokuba i-Kotlin idibene kakhulu, I-Kotlin inokunciphisa inani lekhowudi ye-boilerplate ekufuneka abaphuhlisi babhale ngayo. Oku kuwenza lula umsebenzi womphuhlisi kwaye kunciphisa umngcipheko weempazamo. Ukwengeza, ulwimi alusebenzisi ukufinyeza ngenxa yalo. Ikhowudi ye-boilerplate eninzi kakhulu ikhokelela kwiimpazamo ezininzi kunye nexesha elichithiweyo.

Java

Esona sizathu siphambili sokuba kutheni iJava isetyenziselwa ukwenza ii-apps ze-Android kukuba kulula ukufunda kwaye inezinto ezininzi ezinamandla. IJava yenye yezona lwimi zidumileyo kwihlabathi liphela kwaye inethala leencwadi elityebileyo lezixhobo. Inokugcina abaphuhlisi ixesha elininzi ngokususa isidingo sokukhangela ulwazi oluthile lweprojekthi. Ngaphandle kwale nto, ayilolona lwimi lulungileyo lwabaqalayo.

Ukuqalisa, kufuneka wenze iprojekthi ye-Android kwi-Eclipse IDE. Nje ukuba wenze njalo, ungakhetha inguqulelo ye-Android kunye negama losetyenziso lwakho, kunye nephakheji, iklasi, kunye nendawo yokusebenza. Okulandelayo, kufuneka udale imisebenzi. Imisebenzi yimisebenzi eyahlukeneyo enokwenziwa ngumsebenzisi kwiscreen. Kwakuba kwenziwe oku, i-Eclipse IDE iya kuvula iifayile zoovimba ezifanelekileyo.

Olunye ulwimi oluqhelekileyo olusetyenziselwa ukwenza ii-apps ze-Android yiPython. Ngelixa i-Android ayixhasi uphuhliso lwePython yemveli, kukho iilayibrari zemithombo evulekileyo eyenza kube lula ukuphuhlisa i-app ye-Android kwi-Python. IKivy lelinye lamathala eencwadi, kwaye ikhuthaza uphuhliso olukhawulezayo lweapp. Nangona kunjalo, ukuba awuqhelananga nePython, awuyi konwabela zonke izibonelelo ezibonelelwa yiPython kwii -apps zemveli.

IJava ineenzuzo ezininzi ngaphezulu kweC ++ kunye nePython, kodwa ikwanazo neentsintsi zayo. Abo bakhetha iJava yophuhliso lwe-Android kusenokwenzeka ukuba basebenzise itekhnoloji yakudala. Ngelixa iJava lolona lwimi ludumileyo ukwenza iiapps, I-Kotlin nayo isetyenziswa ngokubanzi. Lulwimi lwanamhlanje, kwaye iyahambelana namathala eencwadi amaninzi eJava.

OnItemLongClickListener

Ukuba unayo i-app ye-Android, ungamilisela iOnItemLongClickListeners-Interface ukubona xa into icofa. Isakhelo siyakubiza i onItemLongClick() indlela ukuba into icofa ixesha elide. Le ndlela ke ithumela umyalezo kwi AlertDialog.

Ukuphumeza i-OnItemLongClickListeners, yenza umsebenzi kwi-app yakho eyenza umsebenzi wokufowuna nanini na xa into ikhethiwe okanye icofa. Xa into icofa ixesha elide, i-Framework ye-Android iya kuyibona njengonqakrazo olude kwaye iya kubonisa isaziso esifutshane se-popup ukubonisa ukuba unqakrazo olude lubhalisiwe.. Ukwengeza, i-OnItemLongClickListening-Interface iqinisekisa ukuba indlela ye-onItemClick iphunyeziwe.. Ukuba uzama ukuphumeza eli nqaku kwi-app ye-Android, qiniseka ukuba ulandela imizekelo.

OnSaveInstanceState()

I-Android kwiSaveInstanceState() indlela igcina imeko yomsebenzisi kunye nayo nayiphi na imisebenzi eguquguqukayo yelungu. Le ndlela ilandelwa yi-onRestoreInstanceState() indlela ebuyisela imeko ye-app xa iqala kwakhona. OnStart() ibuyisela idata kwiviewtatus, enokubandakanya idatha evela kwiimbono ezininzi.

Ukuba umsebenzi wakho uqulethe ulwazi oluninzi, unokufuna ukuyigcina nokuba kukanye. Yiyo loo nto kubalulekile ukufowunela kwiSaveInstanceState() kwi-app yakho ye-Android. Le ndlela igcina imeko yomsebenzi ngokubuyisela i-Bundle-Object kunye nemo yayo. Emva koko, ungasebenzisa le nto ukwenza kwakhona uMsebenzi. Ungasebenzisa kwakhona Iindlela zokuFowuna zeLifecycle ukubuyisela imeko yomsebenzi.

OnSaveInstanceState() ayisoloko ibizwa, ngoko kuya kufuneka uyisebenzise ngononophelo. Yibize kuphela xa umsebenzi wakho ugxile, kwaye ungaze wenze imisebenzi yokugcina idatha ngelixa umsebenzi ungagxininisi. Oku kungenxa yokuba inkqubo ye-Android inokucima umsebenzi ngenxa yendlela yokuziphatha yesiqhelo yesicelo okanye ngokucofa iqhosha elingasemva. Oko kuthetha ukuba umcimbi awusasebenzi.

Olunye uphawu oluluncedo lwe-onSaveInstanceState() kukuba ikuvumela ukuba ugcine i UI-State ye Aktivitat, nto leyo ethetha ukuba igcina imo ye-app. Ukwengeza, le ndlela ingasetyenziselwa ukugcina ngokuqhubekayo. Ingasetyenziselwa ukugcina idatha yoqwalaselo. Xa uhlengahlengiso lutshintsha, ikhowudi ye-Android iya kuyiphatha. Ukwengeza, Ungasebenzisa kwakhona i-Android.screenOrientation kunye ne-android.configUtshintsho lokubonisa i-Toast-Meldings esekwe kuqhelaniso lwekhusi..

Umsebenzi Lifecycle Callbacks

Ukuba wenza i-app ye-Android, Kufuneka ube nolwazi ngoMsebenzi woBomi bokufowunela iiFowuna (I-ALC). Ezi ziindlela ezicelwayo xa umsebenzi uqala okanye uyekwa. Bakunceda ukuba ulawule izixhobo zomsebenzi wakho, bhalisa abaphulaphuli, kwaye zibophelele kwiinkonzo. Unokuzisebenzisa ukugcina idatha yesicelo. Unokufunda ngakumbi malunga nabo kwicandelo elilandelayo. Ezi callbacks ziluncedo kakhulu xa usenza usetyenziso lwe-Android kwaye unokukunceda wenze usetyenziso olusebenzayo ngakumbi.

OnCreate() ibizwa xa kusenziwa umsebenzi, kwaye yenza amacandelo e-UI, izibophelelo, kunye neembono. NgeMiza() ibizwa xa umsebenzi ungena ngasemva okanye uvaliwe. Umsebenzi ophezulu ubiza kuPhakamisa(). Ukuba le ndlela yokufowuna ayibizwa, umsebenzi awuyi kuphinda uvuswe de ube uQalisa kwakhona() iimbuyekezo.

I-OnCreate() Indlela yokusebenza yindlela esisiseko yokuseta umsebenzi owenza ukuqaliswa. Ibhengeza i-UI, ichaza iinguqu zamalungu, kwaye iqwalasela i-app. Ikwabiza SDK_INT, ethintela iinkqubo ezindala ekusebenziseni ii-APIs ezintsha. Android 2.0 (Inqanaba le-API 5) kunye neenguqulelo eziphezulu zixhasa le flegi. Ukuba inkqubo endala isetyenziswa, usetyenziso luya kudibana nomkhethe wexesha lokusebenza.

Umsebenzi weLifecycle Callbacks ikwabizwa ngokuba xa umsebenzi utshintsha imeko. I-OS ifowunela i-onCreate() callback ukuba umsebenzi wenziwa, kwiResume() ukuba iphinda iqaliswe, kwi Misa() xa umsebenzi ungaphambili, kwaye onDestroy() xa umsebenzi utshatyalalisiwe. Ukuba ubhala ngaphezulu enye yezi callbacks, kufuneka ubize indlela yodidi oluphezulu. Kungenjalo, umsebenzi usenokutshayisa okanye uphele ukwimeko engaqhelekanga.