AndroidXとKotlin Coroutines

Transcript

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   AndroidXͱKotlin Corou.nes @takuji31 ؼ͖ͬͯͨؔ੢ϞόΠϧΞϓϦݚڀձ

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   ࣗݾ঺հ

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   ࣗݾ঺հ • @takuji31 id:takuji31 • Takuji Nishibayashi • Hatena Co.,

   Ltd. • App Team • ίϛοΫDAYS • δϟϯϓϧʔΩʔʂ • ΧΫϤϜ
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   ࣗݾ঺հ • Android • Kotlin • Flu-er • ! h-ps:/

   /blog.takuji31.jp • " h-ps:/ /nazuna.takuji31.jp • # $ h-ps:/ /photo.takuji31.jp
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   AndroidX

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   LiveData? ViewModel? AppCompat? Naviga5on

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   ࢖ͬͯ·͢ΑͶ

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   Kotlin Corou+nes

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   ࢖ͬͯ·͔͢ʁ

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    Google I/O 2019

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    Android development will become increasingly Kotlin-first — h$ps://android-developers.googleblog.com/2019/05/google- io-2019-empowering-developers-to-build-experiences-on-Android- Play.html

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    AndroidXʹ΋Kotlinαϙʔτ͕ଓʑ

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    Ұ෦ → h$ps:/ /speakerdeck.com/ takuji31/androidxniqian-mubian-li- nayatura

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    ࠓ೔͸Corou%neαϙʔτͷ࿩Λ͠ ·͢

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    α൛ͷ΋ͷ΋ؚ·ΕΔͷͰ ͝ར༻͸ܭըతʹ

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    ViewModel.viewModelScope

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    ViewModelͷonClearedͰΩϟϯ ηϧ͞ΕΔCoroutineScope

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    ViewModel಺ͰCorou,neΛ࢖͍΍ ͘͢ͳΔ

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    Dispatcher͸ Dispatchers.Main͕ઃఆ͞ΕΔ

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    ໌ࣔతʹࢦఆ͠ͳ͍ݶΓશͯͷॲཧ ͕ϝΠϯεϨουͰ࣮ߦ

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    class UserViewModel : ViewModel() { val name: MutableLiveData<String> = MutableLiveData()

    init { viewModelScope.launch { try { val user = withContext(Dispatchers.Default) { userRepository.fetchMyUser() } name.value = user.name } catch (e: IOException) { // error handling } } } }
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    class UserViewModel : ViewModel() { val name: MutableLiveData<String> = MutableLiveData()

    init { viewModelScope.launch { try { val user = withContext(Dispatchers.Default) { userRepository.fetchMyUser() } name.value = user.name } catch (e: IOException) { // error handling } } } }
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    class UserViewModel : ViewModel() { val name: MutableLiveData<String> = MutableLiveData()

    init { viewModelScope.launch { try { val user = withContext(Dispatchers.Default) { userRepository.fetchMyUser() } name.value = user.name } catch (e: IOException) { // error handling } } } }
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    class UserViewModel : ViewModel() { val name: MutableLiveData<String> = MutableLiveData()

    init { viewModelScope.launch { try { val user = withContext(Dispatchers.Default) { userRepository.fetchMyUser() } name.value = user.name } catch (e: IOException) { // error handling } } } }
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    class UserViewModel : ViewModel() { val name: MutableLiveData<String> = MutableLiveData()

    init { viewModelScope.launch { try { val user = withContext(Dispatchers.Default) { userRepository.fetchMyUser() } name.value = user.name } catch (e: IOException) { // error handling } } } }
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    class UserViewModel : ViewModel() { val name: MutableLiveData<String> = MutableLiveData()

    init { viewModelScope.launch { try { val user = withContext(Dispatchers.Default) { userRepository.fetchMyUser() } name.value = user.name } catch (e: IOException) { // error handling } } } }
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    class UserViewModel : ViewModel() { val name: MutableLiveData<String> = MutableLiveData()

    init { viewModelScope.launch { try { val user = withContext(Dispatchers.Default) { userRepository.fetchMyUser() } name.value = user.name } catch (e: IOException) { // error handling } } } }
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    class UserViewModel : ViewModel() { val name: MutableLiveData<String> = MutableLiveData()

    init { viewModelScope.launch { try { val user = withContext(Dispatchers.Default) { userRepository.fetchMyUser() } name.value = user.name } catch (e: IOException) { // error handling } } } }
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    class UserViewModel : ViewModel() { val name: MutableLiveData<String> = MutableLiveData()

    init { viewModelScope.launch { try { val user = withContext(Dispatchers.Default) { userRepository.fetchMyUser() } name.value = user.name } catch (e: IOException) { // error handling } } } }
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    ※DispatcherΛઃఆ͠ͳ͍··ॏ͍ ॲཧΛ͠ͳ͍

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    LifecycleOwner .lifecycleScope

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    Lifecycleͱ࿈ಈͨ͠ CoroutineScope

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    Lifecycle.State.DESTROYED ʹͳͬͨ࣌ʹΩϟϯηϧ͞ΕΔ CoroutineScope

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    whenCreated / whenStarted / whenResumed

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    fun onCreate(savedInstanceState: Bundle?) { lifecycleScope.launch { whenResumed { val user

    = withContext(Dispatchers.Default) { try { userRepository.fetchMyUser() } catch (e: IOException) { null } } if (user == null) { showErrorAndFinish() } viewModel.setup(user) } } }
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    fun onCreate(savedInstanceState: Bundle?) { lifecycleScope.launch { whenResumed { val user

    = withContext(Dispatchers.Default) { try { userRepository.fetchMyUser() } catch (e: IOException) { null } } if (user == null) { showErrorAndFinish() } viewModel.setup(user) } } }
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    fun onCreate(savedInstanceState: Bundle?) { lifecycleScope.launch { whenResumed { val user

    = withContext(Dispatchers.Default) { try { userRepository.fetchMyUser() } catch (e: IOException) { null } } if (user == null) { showErrorAndFinish() } viewModel.setup(user) } } }
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    fun onCreate(savedInstanceState: Bundle?) { lifecycleScope.launch { whenResumed { val user

    = withContext(Dispatchers.Default) { try { userRepository.fetchMyUser() } catch (e: IOException) { null } } if (user == null) { showErrorAndFinish() } viewModel.setup(user) } } }
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    fun onCreate(savedInstanceState: Bundle?) { lifecycleScope.launch { whenResumed { val user

    = withContext(Dispatchers.Default) { try { userRepository.fetchMyUser() } catch (e: IOException) { null } } if (user == null) { showErrorAndFinish() } viewModel.setup(user) } } }
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    liveData()

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    Corou%neΛLiveDataʹม׵

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    class UserViewModel : ViewModel() { val userName: LiveData<String> = liveData

    { val user = userRepository.fetchMyUser() emit(user.name) } }
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    class UserViewModel : ViewModel() { val userName: LiveData<String> = liveData

    { val user = userRepository.fetchMyUser() emit(user.name) } }
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    class UserViewModel : ViewModel() { val userName: LiveData<String> = liveData

    { val user = userRepository.fetchMyUser() emit(user.name) } }
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    class UserViewModel : ViewModel() { val userName: LiveData<String> = liveData

    { val user = userRepository.fetchMyUser() emit(user.name) } }
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    class UserViewModel : ViewModel() { val userName: LiveData<String> = liveData

    { val user = userRepository.fetchMyUser() emit(user.name) } }
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    Ҿ਺ͷblock͕suspended func.on

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    LiveData͕Ac*veʹͳͬͨ࣌ʹblock ͷॲཧ͕࣮ߦ͞ΕΔ

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    ྫ֎͕ൃੜͨ͠ΒͦΕҎ߱͸஋͕ྲྀ Εͳ͍

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    ͦͷଞ

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    ͦͷଞ • CoroutineWorker • Work ManagerͷWorkerͷdoWork͕suspended func2onͳόʔδϣϯ • όοΫάϥ΢ϯυͰඇಉظॲཧΛ͍ͨ࣌͠ʹ࢖͑ͦ͏ •

    room-ktx • RoomͷDAOͷϝιουʹsuspended func2on͕࢖͑Δ • @Transac2onͱ஫ऍͨ͠ϝιουΛݺͿͱੜ੒͞ΕΔDAOͷϝιου ͕τϥϯβΫγϣϯͰ·ͱΊΒΕΔ
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    h"ps:/ /developer.android.com/ topic/libraries/architecture/ corou6nes

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    Enjoy Kotlin Corou.nes life!