AndroidXとKotlin Coroutines

Transcript

1. AndroidXͱKotlin Corou.nes
   @takuji31
   ؼ͖ͬͯͨؔ੢ϞόΠϧΞϓϦݚڀձ
   

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2. ࣗݾ঺հ
   

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3. ࣗݾ঺հ
   • @takuji31 id:takuji31
   • Takuji Nishibayashi
   • Hatena Co., Ltd.
   • App Team
   • ίϛοΫDAYS
   • δϟϯϓϧʔΩʔʂ
   • ΧΫϤϜ
   

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4. ࣗ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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5. AndroidX
   

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6. LiveData?
   ViewModel?
   AppCompat?
   Naviga5on
   

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7. ࢖ͬͯ·͢ΑͶ
   

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8. Kotlin Corou+nes
   

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9. ࢖ͬͯ·͔͢ʁ
   

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10. Google I/O 2019
    

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11. 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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12. AndroidXʹ΋Kotlinαϙʔτ͕ଓʑ
    

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

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14. ࠓ೔͸Corou%neαϙʔτͷ࿩Λ͠
    ·͢
    

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15. α൛ͷ΋ͷ΋ؚ·ΕΔͷͰ
    ͝ར༻͸ܭըతʹ
    

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16. ViewModel.viewModelScope
    

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17. ViewModelͷonClearedͰΩϟϯ
    ηϧ͞ΕΔCoroutineScope
    

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18. ViewModel಺ͰCorou,neΛ࢖͍΍
    ͘͢ͳΔ
    

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19. Dispatcher͸
    Dispatchers.Main͕ઃఆ͞ΕΔ
    

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20. ໌ࣔతʹࢦఆ͠ͳ͍ݶΓશͯͷॲཧ
    ͕ϝΠϯεϨουͰ࣮ߦ
    

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21. class UserViewModel : ViewModel() {
    val name: MutableLiveData = 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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22. class UserViewModel : ViewModel() {
    val name: MutableLiveData = 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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23. class UserViewModel : ViewModel() {
    val name: MutableLiveData = 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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24. class UserViewModel : ViewModel() {
    val name: MutableLiveData = 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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25. class UserViewModel : ViewModel() {
    val name: MutableLiveData = 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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26. class UserViewModel : ViewModel() {
    val name: MutableLiveData = 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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27. class UserViewModel : ViewModel() {
    val name: MutableLiveData = 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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28. class UserViewModel : ViewModel() {
    val name: MutableLiveData = 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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29. class UserViewModel : ViewModel() {
    val name: MutableLiveData = 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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30. ※DispatcherΛઃఆ͠ͳ͍··ॏ͍
    ॲཧΛ͠ͳ͍
    

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31. LifecycleOwner
    .lifecycleScope
    

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32. Lifecycleͱ࿈ಈͨ͠
    CoroutineScope
    

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33. Lifecycle.State.DESTROYED
    ʹͳͬͨ࣌ʹΩϟϯηϧ͞ΕΔ
    CoroutineScope
    

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34. whenCreated / whenStarted /
    whenResumed
    

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35. 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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36. 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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37. 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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38. 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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39. 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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40. liveData()
    

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41. Corou%neΛLiveDataʹม׵
    

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

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

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

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

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

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47. Ҿ਺ͷblock͕suspended func.on
    

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48. LiveData͕Ac*veʹͳͬͨ࣌ʹblock
    ͷॲཧ͕࣮ߦ͞ΕΔ
    

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49. ྫ֎͕ൃੜͨ͠ΒͦΕҎ߱͸஋͕ྲྀ
    Εͳ͍
    

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50. ͦͷଞ
    

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51. ͦͷଞ
    • CoroutineWorker
    • Work ManagerͷWorkerͷdoWork͕suspended func2onͳόʔδϣϯ
    • όοΫάϥ΢ϯυͰඇಉظॲཧΛ͍ͨ࣌͠ʹ࢖͑ͦ͏
    • room-ktx
    • RoomͷDAOͷϝιουʹsuspended func2on͕࢖͑Δ
    • @Transac2onͱ஫ऍͨ͠ϝιουΛݺͿͱੜ੒͞ΕΔDAOͷϝιου
    ͕τϥϯβΫγϣϯͰ·ͱΊΒΕΔ
    

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52. h"ps:/
    /developer.android.com/
    topic/libraries/architecture/
    corou6nes
    

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53. Enjoy Kotlin Corou.nes life!
    

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