Google I/O 2021結束了, 都有什么精彩內容呢?
Android部分的Playlist附上: Android & Play at Google I/O 2021
Developer Keynote (Google I/O '21)
對於Android的部分來說, 主要是:
Android 12
- user safety.
- performance; improved app startup; customizable launch animations.
- user experience; widgets.
Create beautiful apps, easier
現代化的Android開發.
- Android Studio的升級.
- Kotlin: Kotlin Symbol Processing.
- Jetpack: 各種libraries和Compose.
Build across screens.
- 各種屏幕.
- Voice.
- Watches: Health services.
The top 3 things to know in Modern Android Development | Android @ Google I/O'21
Android開發的三個top topic:
- Jetpack: 一系列的Jetpack libraries發布了新版.
- Tooling: Android Studio的升級, 有了WorkManager Inspector, UI的Inspector支持了View和Compose.
- Kotlin.
What's new in Android | Keynote
Android 12 -> S.
@Deprecated-> deprecated.- Color.
- Widgets.
- Launch animations: 系統自帶啟動動畫, 可以定制.
- Notifications: 新的template style;
Trampoline(?) 優化點開notification的那個短暫延遲. - Toasts: 帶icon, 說明是哪個app彈的toasts; 控制個數.
- Picture in Picture的改善.
- ImageView有個setRenderEffect可以模糊照片了.
- 可以用theme定制模糊.
- list的彈力拉伸效果. (我自己起的名字, 其實人家叫stretch overscroll).
- Graphics: AVIF. 可以過濾支持的media類型.
- Privacy: 關於permission的一些改進; 剪貼板內容會有toast說明來源; foreground restrictions.
What’s new in Android development tools | Session
Android Studio版本號設計.
- Preview工具可以設置橫屏, 定制尺寸, 顯示blueprints, play animation. Compose的preview有交互模式.
- Accessibility test framework scanner.
- 適配多種屏幕: Layout validation.
- 折疊屏, 手表.
- 模擬器還可以模擬heart rate.
- snapshots test.
- WorkManager的tasks.
- Migrate to Non-Transitive R Classes...
What’s new in Jetpack | Session
解釋了Jetpack的初衷和現狀.
alpha和beta版本的意思.
- Experimental Annotations -> Stable.
- CameraX -> Stable.
- AppSearch -> Alpha.
- DataStore -> 用來取代SharedPreferences.
- Security Crypto -> Stable.
- Hilt -> Stable.
- WorkManager -> Stable. (Android Studio也推出了新的WorkManager Inspector.)
- Room -> Stable.
- ConstraintLayout -> Stable. MotionLayout + Motion Editor.
- Fragment -> Stable.
(詳見release notes: https://developer.android.com/jetpack/androidx/releases/fragment.)
重建了FragmentManager; 新增了get result的callback; 廢棄了一些API, 並且Fragment StrictMode可以檢測項目中是否還在使用. - Navigation -> Alpha. 現在支持多個backstacks.
- Google Shortcuts -> Alpha.
- EmojiCompat -> Alpha. (AppCompat 1.4.0以后默認包含.)
- Paging -> Stable.
- Macrobenchmark -> Alpha. (app啟動和滾動效率; local/CI.)
- Compose integrations.
What's new in Jetpack Compose | Session
為什么我們需要一個全新的UI Toolkit呢. -> 為了適應更加現代化的開發方式.
faster & easier.
Compose將數據轉換成UI.
Checkbox的例子:
UI完全由參數控制. -> single source of truth. 沒有其他的狀態需要sync.
把參數和回調提到方法參數中去:
- You completely describe your UI for a given state.
- The framework updates your UI when the state changes.
這里有個圖, 推薦ViewModel暴露一個Screen狀態, 集中管理, 然后下發到每個composable.
這樣也利於測試.
Compose實現了material design, 提供了組件, 還有theming system.
有一個owl app的實現解說.
和傳統view的interop.
State of Kotlin on Android | Session
- Kotlin變得越來越流行, 不僅app, 還有server.
- Kotlin Symbol Processing目前發布了alpha.
- 編譯器的升級.
- 好多好多的ktx庫.
- protobuf的支持: https://developers.google.com/protocol-buffers/docs/kotlintutorial
- coroutines的debugger -> coming soon. 可以在線程之間跳轉, 查看信息.
What’s new in Android Gradle plugin | Session
New APIs in the Android Gradle Plugin
Using Jetpack libraries in Compose | Session
Jetpack Compose和Jetpack中其他庫可以很好的結合使用.
Top 12 tips to get ready for Android 12 | Session
Getting Ready for Android 12.
- Developer Options -> App Compatibility Changes.
- Foreground services were designed for multi-tasking and completing a user action. -> 從后台啟動foreground services將被限制.
- Expedited Jobs with WorkManager APIs.
- User may turn off the mic and camera sensors using mic and camera toggles.
- Apps that have not been used for an extended period will be hibernated. (permissions, storage, services)
- Nearby device permission. Decouple Bluetooth scanning from Location.
- MAC address restriction.
- Safe component exporting. 有intent filter就必須顯式聲明exported.
- Custom notifications deprecation.
- App link improvements.
- WebView Samesite.
- New stretch overscroll.