Peb npaj koj qhov kev pom! Kev ua tau zoo nrog ONMA scout android app kev txhim kho yog lav.
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Yog tias koj tab tom nrhiav ib txoj hauv kev los kawm yuav ua li cas los tsim ib daim ntawv thov Android, Tom qab ntawd koj yuav tsum xav txog kev kawm hauv Android Apps Programmieren. Cov chav kawm no zoo meej rau cov pib tshiab, raws li lawv tsis tas yuav muaj kev paub dhau los lossis keeb kwm yav dhau los. Koj yuav kawm Java, Kotlin, Luag-thiab-nco, thiab kev xav. Tom qab kawm tiav hoob no, koj yuav muaj kev nkag siab zoo ntawm Android programming. Txawm li cas los, koj yuav tsum paub txog qee cov ntsiab lus tseem ceeb ua ntej pib qhov kev kawm no.
Yog tias koj txaus siab kawm cov hauv paus ntawm Android app programmieren hauv Java, koj yuav xav tau kev paub lus zoo. Java yog hom lus siv dav tshaj plaws rau Android thiab yog hom lus nyiam los tsim cov apps mobile. Hoob no suav nrog Java Basics thiab qhia txog Object-Oriented Programming. Koj tseem yuav kawm yuav ua li cas ua haujlwm nrog Android studio, ib tug nrov app txhim kho cuab yeej. Thaum kawm, koj yuav tsim ib qhov project hauv Android thiab tshawb nrhiav cov hauv paus ntawm kev tsim ib qho Android app.
Thaum cov txheej txheem txheej txheem ntawm Android app programmieren hauv Java yog nrov, lawv tseem muaj kev txwv tsis pub dhau lawv lub peev xwm. Thaum txoj kev no zoo rau kev tsim cov apps yooj yim hauv Android, koj yuav tau hloov Java code yog tias koj xav ntxiv nta ntxiv. Koj yuav tsum kawm Java zoo, thiab nws tsis yog rau txhua tus. Cov neeg ua lag luam feem ntau xaiv ntiav ib tus kws tshaj lij Android app tsim los ua haujlwm ntawm lawv cov apps.
Yog tias koj yog tus tshaj plaws Android programmer, Koj tuaj yeem siv Async-Task-Framework thiab siv Intents los xaiv cov haujlwm. Koj tseem tuaj yeem siv Android Studio's built-in logging system ua rau koj Android app yuam kev-dawb. Thiab koj yuav zoo siab koj tau ua yog tias koj cov apps ua haujlwm raws li qhov xav tau. Tsuas yog xyuas kom tseeb tias koj txheeb xyuas qhov kaw lus ua ntej xa lawv mus rau lub khw app.
Yog tias koj tab tom sim sau Android app, Tej zaum koj yuav xav txog kev siv Kotlin. Cov lus programming tshiab no rau Android apps yog qhov kev xaiv zoo vim nws qhov yooj yim. Nws txoj kev yooj yim yog qhov tseem ceeb uas yuav tsum nco ntsoov, raws li kev kawm Kotlin tuaj yeem nyuaj. Txawm li cas los, ib zaug koj tau paub qhov pib ntawm Java, Koj yuav nyiam ua haujlwm nrog Kotlin. Tsis yog nws ua rau koj lub neej yooj yim dua, tab sis nws kuj muaj kev nyab xeeb thiab platform agnostic.
Lub Android-App muaj ntau yam haujlwm, ib qho rau txhua qhov screen. Tom qab ua tiav ib qho haujlwm, koj txav mus rau lwm qhov. Cov haujlwm tseem ceeb hauv ib qho app yog MainActivity, uas yog chav kawm Java thiab subclass ntawm Android chav ua haujlwm thiab AppCompatActivity. Nws yog lub ntsiab lus nkag rau lub app thiab muaj cov txheej txheem zoo li qub() thiab onCreate().
Tom qab koj kawm cov hauv paus ntawm Kotlin, koj yuav tsum xav txog kev kawm yuav ua li cas los tsim ib daim ntawv thov Android siv nws. Muaj ntau ntau cov kev pabcuam los kawm paub siv Kotlin rau Android, thiab koj tuaj yeem ua raws nrog rau qhov project. Ib chav kawm pub dawb uas siv txoj hauv kev los pab koj txhim kho koj cov txuj ci Kotlin. Yog xav paub ntxiv, tshawb xyuas cov kev kawm uas muaj los ntawm Google lossis Udacity.
Txhawm rau rub-thiab-nco hauv koj lub Android app, koj yuav tsum paub cov ntsiab lus hais txog yuav ua li cas rub-thiab-poob mechanism ua haujlwm. Drag-and-poob cov xwm txheej tuaj yeem tshwm sim los ntawm txhua lub cuab yeej los ntawm kev ua rau tus neeg siv qhov tshwm sim, thiab Android lub moj khaum muab cov chav kawm rub cov xwm txheej thiab rub cov neeg mloog rau txhua qhov haujlwm. Tus txheej txheem luag yog yooj yim heev: lub hauv paus app ua rau luag tshwm sim los ntawm kev xa ib tug startDrag() hu rov qab rau qhov system. Qhov no callback ces muab luag cov ntaub ntawv rau lub system. Tom qab tuav lub luag, lub hauv paus app tuaj yeem hu rau qhov kev tshwm sim poob los xyuas seb nws puas tau ua tiav.
Lub hauv paus ntsiab lus rub-thiab-nco hauv Android tso cai rau cov neeg siv txav cov ntaub ntawv ntawm ntau yam khoom hauv kev ua ub no. Lub luag haujlwm chav kawm, cov neeg mloog, thiab cov chav kawm yog tsim los txhawb cov ntaub ntawv txav. Koj tuaj yeem siv lub luag haujlwm rub los ua lwm yam haujlwm UI. Ntxiv nrog rau kev txav cov ntaub ntawv ntawm cov khoom, nws kuj tseem siv tau los tsim kev sib tham sib navigation thiab lwm yam nta. Txawm li cas los, rau cov yam ntxwv siab heev, koj yuav tsum xav txog kev siv luag-thiab-nco hauv koj daim ntawv thov ua ntej.
Koj yuav tsum sau npe ua tus mloog kom rub cov xwm txheej. Luag cov xwm txheej tshwm sim thaum twg tus neeg siv txav los yog tso tawm cov khoom Saib. Cov xwm txheej raug xa mus rau cov neeg mloog thiab hu xov tooj rov qab. Cov txheej txheem no tau txais cov ntaub ntawv thiab txiav txim siab seb puas yuav txais lossis tsis lees txais. Koj tuaj yeem siv cov hau kev no los hloov qhov tsos ntawm View object. Thaum koj npaj txhij los tsim ib qho app nrog luag-thiab-nco nta, koj yuav tsum paub txog cov hauv paus ntawm kev rub-thiab-poob Android app programming.
Lub hom phiaj yog siv los txav los ntawm ib qho haujlwm mus rau lwm qhov hauv daim ntawv thov Android. Lub hom phiaj ua rau koj hloov ntawm ib qho haujlwm mus rau lwm qhov los ntawm kev siv ib hom lus tshwj xeeb. Nyob rau hauv sib piv rau ib txwm siv PC, uas tsuas muaj ib qho screen xwb, Android apps tuaj yeem muaj ntau qhov screen nplooj ntawv, txhua tus mob siab rau ib qho haujlwm tshwj xeeb. Cov nplooj ntawv tshuaj ntsuam no tau nkag los ntawm tus neeg siv hauv lub hom phiaj ua haujlwm. Lub hom phiaj pab koj tsim cov ntawv thov mobile zoo dua.
Lub hom phiaj tseem tuaj yeem siv los dhia ntawm daim ntawv thov mus rau daim ntawv thov. Ntau tus neeg siv Android pom dhia ntawm ib daim ntawv thov mus rau lwm qhov. Piv txwv li, yog tias tus neeg siv tau txais qhov txuas them nyiaj, lawv tuaj yeem qhib daim ntawv thov PayPal lossis GPay. Hauv cov xwm txheej zoo li no, lub kaw lus tuaj yeem teb tau los ntawm kev dhau Lub Hom Phiaj rau tus neeg siv. Lub hom phiaj tso cai rau koj txav los ntawm ib qho app mus rau lwm qhov yooj yim. Koj tuaj yeem siv lawv los tsim ib daim ntawv thov tshiab nkaus!
Kev xav ua haujlwm sib txawv hauv txhua kis. Yog tias koj xav tso saib cov ntaub ntawv hais txog cov nqi Tshuag, koj tuaj yeem siv txoj haujlwm asynchronous hu ua “ListView”. Qhov no app qhia cov ntaub ntawv los ntawm cov npe saib thaum tus neeg siv nyem rau ntawm lub mloog pob ntseg. Tib yam mus rau npe cov ntaub ntawv nyiaj txiag hauv ib qho app. Ntxiv mus, Koj tuaj yeem siv cov haujlwm asynchronous rau kev ua haujlwm nyuaj, xws li nkag mus rau hauv Internet lossis tshawb xyuas koj tus email.
Ib txoj hauv kev zoo tshaj plaws los tiv thaiv daim ntawv thov Android yog siv sandboxing. Cov txheej txheem no tiv thaiv lub operating system los ntawm kev siv tsis zoo los ntawm kev khiav lub app hauv nws tus kheej “qhov chaw.” Qhov no tiv thaiv tus neeg siv lub cuab yeej los ntawm kev cuam tshuam ntawm lwm cov apps. Siv sandboxing yog ib qho yooj yim heev thiab yuav ua rau koj Android app muaj kev nyab xeeb rau koj cov neeg siv. Kawm paub siv sandboxing rau Android app programming, nyeem rau.
Piv txwv li, xav tias koj xav tso saib cov shares ntawm koj cov neeg siv. Ces, Koj tuaj yeem siv BufferedReader thiab InputStream los nyeem cov ntaub ntawv. Siv InputStream, koj tuaj yeem siv cov ntaub ntawv nyiaj txiag simulated los qhia cov ntsiab lus ntawm cov lus teev tseg. Koj tuaj yeem siv tib txoj hlua no los tso saib cov lus rau cov neeg siv. Thaum koj siv Internet, Android system xav tau txoj haujlwm asynchronous. Qhov no hu ua HoleDatenTask, thiab nws khiav hauv keeb kwm yav dhau.
Android's sandbox siv tus neeg siv ID los tsim kev ruaj ntseg ntawm cov apps thiab cov txheej txheem. Nws cov qauv kev ruaj ntseg tswj kev sib cais ntawm cov txheej txheem thiab cov neeg siv. Nws kuj tswj kev nkag mus rau cov ntaub ntawv uas tsis cuam tshuam nrog daim ntawv thov. Qhov no tiv thaiv lub cuab yeej los ntawm cov apps phem. Sandbox yog qhov yooj yim, auditable, thiab yog raws li UNIX-style cov neeg siv sib cais ntawm cov txheej txheem. Nws kuj tswj cov ntaub ntawv tso cai. Hauv luv, nws ua rau Android system muaj kev nyab xeeb los ntawm kev siv tsis zoo.
Yog tias koj tshiab rau Android programming, Tej zaum koj yuav xav tsis thoob qhov twg yuav pib. Hmoov zoo, muaj ob peb qhov kev pab cuam los pab koj pib. Siv cov cuab yeej txhim kho hauv Android zoo li Android Studio yog ib txoj hauv kev yooj yim tshaj plaws los pib. Nws kuj yog dawb, yog li tsis muaj laj thawj tos kom txog thaum koj yog tus kws tshaj lij los pib! Hoob no yuav qhia koj txog cov hauv paus ntawm Java thiab Android programming. Nws tseem hais txog yuav ua li cas los tsim ib qho app thiab tsim kev ua si.
Thawj zaj lus qhia ntawm Android programming pib nrog kev taw qhia rau Lub Qhov Ncauj Cov Ntaub Ntawv thiab Cov Neeg Mloog-Cov Khoom, uas yog lub luag haujlwm rau kev txheeb xyuas cov neeg siv tswv yim. Nws mam li npog cov chav kawm tsis qhia npe thiab kev kho mob tshwm sim. Ntxiv rau, cov tub ntxhais kawm yuav kawm txog kev npaj rau Quellcode, Java programmation tool rau Android. Cov cuab yeej no ua rau nws yooj yim los tsim Listener-Objects thiab txhim kho qhov pom ntawm koj cov cai.
Yog tias koj yog tus tsim tawm tab tom nrhiav tsim Android app, Java yog ib feem tseem ceeb ntawm cov txheej txheem. Tsim ib haiv neeg hauv app nrog JavaScript yuav tsum muaj SDK, xws li Android Studio. Tsis zoo li web applications, haiv neeg Android apps tuaj yeem nkag mus ncaj qha rau txhua qhov khoom siv mobile thiab software, nrog rau lub koob yees duab thiab microphone. Vim li no, yog tias koj yog tus tsim tawm, koj yuav muaj qhov zoo dua cov neeg tsim khoom siv iOS lossis Windows.
Thaum nws muaj peev xwm tsim Android apps siv lwm hom lus, Java yog hom lus programming rau lub platform. Thaum muaj lwm yam lus programming, ntau tus thawj coj lag luam tau hloov mus rau Kotlin los sau lawv daim ntawv thov. Twitter, Pinterest, Uber, thiab AirBnB txhua tus ua qhov hloov mus siv Kotlin. Koj tuaj yeem kawm paub ntau ntxiv txog nws los ntawm kev nyeem peb cov lus qhia Kotlin-Yuav ua li cas-rau.
Qhov zoo ntawm kev siv Java los tsim Android apps muaj ntau heev. Cov lus yooj yim kawm, yooj yim mus debug, thiab sau ua ke, thiab yog object-oriented, tso cai rau cov neeg tsim khoom sau cov kev pabcuam modular uas rov siv cov lej. Ntxiv thiab, Java yog cross-platform, ua kom yooj yim txav code ntawm lub tshuab computer. Ntxiv rau, Java yog sib xws nrog Android cov khoom siv txhim kho, ua rau nws yog qhov kev xaiv zoo tshaj plaws rau ntau yam haujlwm.
Thaum tsim Android apps, Nws yog ib qho tseem ceeb kom paub tias koj lub hom phiaj cov neeg tuaj saib yog dab tsi thiab lawv xav tau dab tsi los ntawm lub app. Yog tias koj lub hom phiaj cov neeg tuaj saib feem ntau yog cov hluas, koj tuaj yeem siv hom lus C ++. Txawm li cas los, Koj yuav tsum nco ntsoov tias C ++ tsis yog tus siv zoo li Java, yog li koj yuav xav xav txog lwm hom lus programming. Txawm li cas los xij, koj yuav tsum xaiv hom lus uas ua rau koj lub hom phiaj cov neeg tuaj saib zoo siab. Yog tias koj tsis paub Java, Koj tuaj yeem sim Objective-C. Qhov no yog ib hom lus dav dav-oriented programming lus keeb kwm tsim los ntawm Tom Love thiab Brad Cox rau Smalltalk-80 systems.