ما هي ActivityLifecycleCallbacks؟

public interface ActivityLifecycleCallbacks {    void onActivityCreated(Activity activity, Bundle savedInstanceState);    void onActivityStarted(Activity activity);    void onActivityResumed(Activity activity);    void onActivityPaused(Activity activity);    void onActivityStopped(Activity activity);    void onActivitySaveInstanceState(Activity activity, Bundle outState);    void onActivityDestroyed(Activity activity); } 

 public interface ActivityLifecycleCallbacks {   default void onActivityPreCreated( @NonNull Activity activity, @Nullable Bundle savedInstanceState) { }   void onActivityCreated( @NonNull Activity activity, @Nullable Bundle savedInstanceState);   default void onActivityPostCreated( @NonNull Activity activity, @Nullable Bundle savedInstanceState) { }   default void onActivityPreStarted(@NonNull Activity activity) { }   void onActivityStarted(@NonNull Activity activity);   default void onActivityPostStarted(@NonNull Activity activity) { }   default void onActivityPreResumed(@NonNull Activity activity) { }   void onActivityResumed(@NonNull Activity activity);   default void onActivityPostResumed(@NonNull Activity activity) { }   default void onActivityPrePaused(@NonNull Activity activity) { }   void onActivityPaused(@NonNull Activity activity);   default void onActivityPostPaused(@NonNull Activity activity) { }   default void onActivityPreStopped(@NonNull Activity activity) { }   void onActivityStopped(@NonNull Activity activity);   default void onActivityPostStopped(@NonNull Activity activity) { }   default void onActivityPreSaveInstanceState( @NonNull Activity activity, @NonNull Bundle outState) { }   void onActivitySaveInstanceState( @NonNull Activity activity, @NonNull Bundle outState);   default void onActivityPostSaveInstanceState( @NonNull Activity activity, @NonNull Bundle outState) { }   default void onActivityPreDestroyed(@NonNull Activity activity) { }   void onActivityDestroyed(@NonNull Activity activity);   default void onActivityPostDestroyed(@NonNull Activity activity) { } } 

  mFragments.restoreAllState(p, mLastNonConfigurationInstances != null           ? mLastNonConfigurationInstances.fragments : null); } mFragments.dispatchCreate(); getApplication().dispatchActivityCreated(this, savedInstanceState); if (mVoiceInteractor != null) { 

كيفية جعل ActivityLifecycleCallbacks تعمل؟

 class MyApplication : Application() {   override fun onCreate() { super.onCreate() registerActivityLifecycleCallbacks(MyCallbacks()) } } 

ما الذي يمكن القيام به مع هذا؟

 class ThemeCallback( @StyleRes val myTheme: Int ) : ActivityLifecycleCallbacks { override fun onActivityCreated( activity: Activity, savedInstanceState: Bundle? ) { activity.setTheme(myTheme) } } 

 class ThemeCallback( @StyleRes val myTheme: Int ) : ActivityLifecycleCallbacks { override fun onActivityCreated( activity: Activity, savedInstanceState: Bundle? ) { val myPackage = "my.cool.application" activity .takeIf { it.javaClass.name.startsWith(myPackage) } ?.setTheme(myTheme) } } 

 class DialogCallback( val dialogFragment: DialogFragment ) : Application.ActivityLifecycleCallbacks { override fun onActivityCreated( activity: Activity, savedInstanceState: Bundle? ) { if (savedInstanceState == null) { val tag = dialogFragment.javaClass.name (activity as? AppCompatActivity) ?.supportFragmentManager ?.also { fragmentManager -> if (fragmentManager.findFragmentByTag(tag) == null) { dialogFragment.show(fragmentManager, tag) } } } } } 

 class StartingActivityCallback : Application.ActivityLifecycleCallbacks { override fun onActivityCreated( activity: Activity, savedInstanceState: Bundle? ) { if (savedInstanceState == null) { (activity as? AppCompatActivity) ?.supportFragmentManager ?.also { fragmentManager -> val startingFragment = findOrCreateFragment(fragmentManager) startingFragment.listener = { resultCode, data -> // handle response here } // start Activity inside StartingFragment } } } private fun findOrCreateFragment( fragmentManager: FragmentManager ): StartingFragment { val tag = StartingFragment::class.java.name return fragmentManager .findFragmentByTag(tag) as StartingFragment? ?: StartingFragment().apply { fragmentManager .beginTransaction() .add(this, tag) .commit() } } } 

 interface Screen { val screenName: String } 

 class NamedActivity : Activity(), Screen { override val screenName: String = "First screen" } 

 class AnalyticsActivityCallback( val sendAnalytics: (String) -> Unit ) : Application.ActivityLifecycleCallbacks { override fun onActivityCreated( activity: Activity, savedInstanceState: Bundle? ) { if (savedInstanceState == null) { (activity as? Screen)?.screenName?.let(sendAnalytics) } } } 

 interface ScreenWithParameters : Screen { val parameters: Map<String, String> } 

 class NamedActivity : Activity(), ScreenWithParameters { override val screenName: String = "First screen" override val parameters: Map<String, String> = mapOf("key" to "value") } 

 class AnalyticsActivityCallback( val sendAnalytics: (String, Map<String, String>?) -> Unit ) : Application.ActivityLifecycleCallbacks { override fun onActivityCreated( activity: Activity, savedInstanceState: Bundle? ) { if (savedInstanceState == null) { (activity as? Screen)?.screenName?.let { name -> sendAnalytics( name, (activity as? ScreenWithParameters)?.parameters ) } } } } 

 class CoolToolImpl { val extraInfo = "i am dependency" } 

 interface CoolTool { val extraInfo: String } class CoolToolImpl : CoolTool { override val extraInfo = "i am dependency" } 

 interface RequireCoolTool { var coolTool: CoolTool } class CoolToolActivity : Activity(), RequireCoolTool { override lateinit var coolTool: CoolTool } class InjectingLifecycleCallbacks : ActivityLifecycleCallbacks { override fun onActivityCreated( activity: Activity, savedInstanceState: Bundle? ) { (activity as? RequireCoolTool)?.coolTool = CoolToolImpl() } } 

 @RunWith(AndroidJUnit4::class) class DIActivityTest { @Test fun `should access extraInfo when created`() { // prepare val mockTool: CoolTool = mock() val application = getApplicationContext<android.app.Application>() application.registerActivityLifecycleCallbacks( object : Application.ActivityLifecycleCallbacks { override fun onActivityCreated( activity: Activity, savedInstanceState: Bundle? ) { (activity as? RequireCoolTool)?.coolTool = mockTool } }) // invoke launch<DIActivity>(Intent(application, DIActivity::class.java)) // assert verify(mockTool).extraInfo } } 

1. وفقًا للتعليمات ، ننفذ تطبيق DispatchingAndroidInjector ؛
2. إنشاء ActivityLifecycleCallbacks يستدعي DispatchingAndroidInjector.maybeInject () على كل نشاط ؛
3. تسجيل ActivityLifecycleCallbacks في التطبيق.

 class MyApplication : Application() { @Inject lateinit var dispatchingAndroidInjector: DispatchingAndroidInjector<Any> override fun onCreate() { super.onCreate() DaggerYourApplicationComponent.create().inject(this); registerActivityLifecycleCallbacks( InjectingLifecycleCallbacks( dispatchingAndroidInjector ) ) } } class InjectingLifecycleCallbacks( val dispatchingAndroidInjector: DispatchingAndroidInjector<Any> ) : ActivityLifecycleCallbacks { override fun onActivityCreated( activity: Activity, savedInstanceState: Bundle? ) {       dispatchingAndroidInjector.maybeInject(activity) } } 

لتلخيص