public class App extends Application {

    @Override
    public void onCreate() {
        super.onCreate();
        initActivityLifecycleCallbacks();
    }

    /**
     * 在application里监听所以activity生命周期的回调
     */
    private void initActivityLifecycleCallbacks(){
        registerActivityLifecycleCallbacks(new ActivityLifecycleCallbacks() { //添加监听
            @Override
            public void onActivityCreated(Activity activity, Bundle savedInstanceState) {
                //activity创建生命周期
                if(activity instanceof MainActivity){ //判断创建的activity对应对象
                   
                }

            }

            @Override
            public void onActivityStarted(Activity activity) {
                //activity启动生命周期

            }

            @Override
            public void onActivityResumed(Activity activity) {
                //activity恢复生命周期

            }

            @Override
            public void onActivityPaused(Activity activity) {
                //activity暂停生命周期

            }

            @Override
            public void onActivityStopped(Activity activity) {
                //activity停止生命周期

            }

            @Override
            public void onActivitySaveInstanceState(Activity activity, Bundle outState) {
                //保存activity实例状态

            }

            @Override
            public void onActivityDestroyed(Activity activity) {
                //activity销毁生命周期

            }
        });
    }
}