💡【Jetpack】Android Lifecycle 生命週期 範例🔧
Android Lifecycle 是 Android 平台上一個重要的技術,可以讓開發者更好地控制應用程式在各種不同狀態之間的轉換。
它提供了一系列的方法來關聯應用程式元件的生命週期變化,從而允許開發者保持應用程式的一致性和一致性。
Android Lifecycle 也可以為開發者創造更好的應用程式,並且減少資源浪費和記憶體洩漏。
本文將詳細描述 Android Lifecycle 的工作原理和範例,以及使用它的最佳做法。
![](https://developer.android.com/static/images/topic/libraries/architecture/lifecycle-states.svg)
文章目錄
- Lifecycle Application 判斷 Activity 前後台
- Lifecycle
- Developer Documents Lifecycle
1.Lifecycle Application 判斷 Activity 前後台
build.gradle
dependencies {
def lifecycle_version = "2.5.1"
implementation "androidx.lifecycle:lifecycle-process:$lifecycle_version"
}
MyApplication.kt
class MyApplication : Application(), DefaultLifecycleObserver {
override fun onCreate() {
super<Application>.onCreate()
ProcessLifecycleOwner.get().lifecycle.addObserver(this)
}
override fun onStart(owner: LifecycleOwner) {
super.onStart(owner)
Toast.makeText(this, "前台", Toast.LENGTH_SHORT).show()
}
override fun onStop(owner: LifecycleOwner) {
super.onStop(owner)
Toast.makeText(this, "後台", Toast.LENGTH_SHORT).show()
}
}
AndroidManifest.xml
<application
android:name=".MyApplication">
</application>
2.Lifecycle
MyObserver.kt
class MyObserver : DefaultLifecycleObserver {
override fun onCreate(owner: LifecycleOwner) {
super.onCreate(owner)
Log.e(MyObserver::class.java.simpleName, "onCreate")
}
override fun onStart(owner: LifecycleOwner) {
super.onStart(owner)
Log.e(MyObserver::class.java.simpleName, "onStart")
}
override fun onResume(owner: LifecycleOwner) {
super.onResume(owner)
Log.e(MyObserver::class.java.simpleName, "onResume")
}
override fun onPause(owner: LifecycleOwner) {
super.onPause(owner)
Log.e(MyObserver::class.java.simpleName, "onPause")
}
override fun onStop(owner: LifecycleOwner) {
super.onStop(owner)
Log.e(MyObserver::class.java.simpleName, "onStop")
}
override fun onDestroy(owner: LifecycleOwner) {
Log.e(MyObserver::class.java.simpleName, "onDestroy")
super.onDestroy(owner)
}
}
MainActivity.kt
class MainActivity : AppCompatActivity() {
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_main)
lifecycle.addObserver(MyObserver())
}
}
3.Developer Documents Lifecycle
Open in Documents Lifecycle