棒棒糖(Lollipop): 获取顶部活动名称

Question

如何在Lollipop中获取顶部活动名称？

((ActivityManager)getSystemService(Context.ACTIVITY_SERVICE)).
   getRunningTasks(1).get(0).topActivity

不再支持Lollipop版本：

     * @deprecated As of {@link android.os.Build.VERSION_CODES#LOLLIPOP}, this method
     * is no longer available to third party
     * applications: the introduction of document-centric recents means
     * it can leak person information to the caller.  For backwards compatibility,
     * it will still retu rn a small subset of its data: at least the caller's
     * own tasks, and possibly some other tasks
     * such as home that are known to not be sensitive.

在MyActivity的onResume中调用

MyApplication.getInstance().saveCurentActivity(MyActivity.this)
saveCurentActivity(Activity a) {
    this.activityName = a.getClass().getSimpleName();
}

不是一个好主意，因为MyApplication可能会在出现错误（例如NPE）时被销毁。

- VKDev

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请检查我对类似问题的答案。https://dev59.com/oV4c5IYBdhLWcg3wUI0N#36660429 - AmAnDroid

Answer 1

这段代码在我的电脑上能够运行。

ActivityManager activityManager = (ActivityManager)    context.getSystemService(Activity.ACTIVITY_SERVICE);
List<ActivityManager.RunningTaskInfo> taskInfo = activityManager.getRunningTasks(1);
String currentTopActivity = taskInfo.get(0).topActivity.getClassName();

它将给出顶部活动。

- user3863488

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getRunningTasks已被弃用 - VKDev

使用getAppTasks()和getTaskInfo()代替...像下面这样 List<ActivityManager.AppTask> tasks = activityManager.getAppTasks(); ActivityManager.RecentTaskInfo taskInfo = tasks.get(0).getTaskInfo(); - user3863488

Answer 2

这对我有效：

                long end = System.currentTimeMillis();
                long INTERVAL=2000;
                long begin = end - INTERVAL;
                if (Build.VERSION.SDK_INT >= 21) {
                    UsageStatsManager us = (UsageStatsManager) MyServices.this.getSystemService(Context.USAGE_STATS_SERVICE);
                    UsageEvents usageEvents = us.queryEvents(begin, end);
                    while (usageEvents.hasNextEvent()) {
                        UsageEvents.Event event = new UsageEvents.Event();
                        usageEvents.getNextEvent(event);
                        if (event.getEventType() == UsageEvents.Event.MOVE_TO_FOREGROUND) {
                            Log.e("event", "timestamp : " + event.getTimeStamp());
                            Log.e("event", "package name : " + event.getPackageName());
                            Log.e("event", "Class name : " + event.getClassName());
                            //You can find activity name as Class name      

                        }

                    }
                }

- ahmad dehghan

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这是API级别22而不是21。 - 林果皞

Answer 3

我不熟悉您正在使用的原始API，但是您可以使用Application.registerActivityLifecycleCallbacks注册的ActivityLifecycleCallbacks来跟踪应用程序中的活动生命周期更改。每当创建、启动、恢复等活动时，它都会收到通知。您可以使用onActivityResumed和onActivityPaused钩子来跟踪当前活动。

- cwbowron

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好主意，但我该如何存储名称？不要在MyApplication实例中。 - VKDev

你对这些名称做了什么？你能把它们存储在ActivityLifeCycleCallback中并将其作为单例或静态实例吗？ - cwbowron

我需要将当前顶部活动名称保存到变量中以便在我的逻辑中使用。我会尝试您的解决方案，谢谢。 - VKDev