android 使用ActivityLifecycleCallbacks管理activity

• Application通过此接口提供了一套回调方法，用于让开发者对Activity的生命周期事件进行集中处理。

• public class BaseApplication extends Application {
  
      private static final String TAG = "BaseApplication";
  
      private static BaseApplication sInstance;
  
      public static BaseApplication getInstance() {
          return sInstance;
      }
  
      @Override
      public void onCreate() {
          super.onCreate();
          sInstance = this;
          registerActivityLifecycleCallbacks(mCallbacks);
      }
  
      private ActivityLifecycleCallbacks mCallbacks = new ActivityLifecycleCallbacks() {
  
          @Override
          public void onActivityCreated(Activity activity, Bundle savedInstanceState) {
              Log.d(TAG, "onActivityCreated() called with: activity = [" + activity + "], savedInstanceState = [" + savedInstanceState + "]");
          }
  
          @Override
          public void onActivityStarted(Activity activity) {
              Log.d(TAG, "onActivityStarted() called with: activity = [" + activity + "]");
          }
  
          @Override
          public void onActivityResumed(Activity activity) {
              Log.d(TAG, "onActivityResumed() called with: activity = [" + activity + "]");
          }
  
          @Override
          public void onActivityPaused(Activity activity) {
              Log.d(TAG, "onActivityPaused() called with: activity = [" + activity + "]");
          }
  
          @Override
          public void onActivityStopped(Activity activity) {
              Log.d(TAG, "onActivityStopped() called with: activity = [" + activity + "]");
          }
  
          @Override
          public void onActivitySaveInstanceState(Activity activity, Bundle outState) {
              Log.d(TAG, "onActivitySaveInstanceState() called with: activity = [" + activity + "], outState = [" + outState + "]");
          }
  
          @Override
          public void onActivityDestroyed(Activity activity) {
              Log.d(TAG, "onActivityDestroyed() called with: activity = [" + activity + "]");
          }
      };
  }