是否可以使用Usage Stats获取前台活动？

Question

我找到了这个方法来获取前台活动：

public String getRecentActivity(Context context) { //I cut out the pre API 22 part of the method

    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP_MR1) {

        UsageStatsManager mUsageStatsManager = (UsageStatsManager) context.getSystemService(Context.USAGE_STATS_SERVICE);

        long time = System.currentTimeMillis();

        UsageEvents usageEvents = mUsageStatsManager.queryEvents(time - 1000 * 30, System.currentTimeMillis() + (10 * 1000));
        UsageEvents.Event event = new UsageEvents.Event();
        while (usageEvents.hasNextEvent()) {
            usageEvents.getNextEvent(event);
        }

        if (!TextUtils.isEmpty(event.getPackageName()) && event.getEventType() == UsageEvents.Event.MOVE_TO_FOREGROUND) {
            return event.getPackageName();
        }
    }
    return " ";
}

这就是问题所在:当有一个前台服务在运行时，这个方法返回一个空的包名，而不是前台活动的包名(即return " ";)。如何让它返回前台活动？有没有办法从usageEvents中过滤掉服务？

Answer 1

如果使用queryUsageStates而不是quertEvent，我希望它能修复

public String getRecentActivity(){
        String mpackageName = "";
        UsageStatsManager usage = (UsageStatsManager) getSystemService(Context.USAGE_STATS_SERVICE);
        long time = System.currentTimeMillis();
        List<UsageStats> stats = usage.queryUsageStats(UsageStatsManager.INTERVAL_DAILY, time - 1000 * 30, time);
        if (stats != null) {
            SortedMap<Long, UsageStats> runningTask = new TreeMap<Long, UsageStats>();
            for (UsageStats usageStats : stats) {
                runningTask.put(usageStats.getLastTimeUsed(), usageStats);
            }

            if (runningTask.isEmpty()) {
                mpackageName = "";
            } else {
                mpackageName = runningTask.get(runningTask.lastKey()).getPackageName();
            }
        }
        return mpackageName;
    }

Answer 2

如果有人想知道答案，我想出来了：

public String getRecentActivity(Context context) { //Only works for APIs above or equal to 22

    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP_MR1) {

        UsageStatsManager mUsageStatsManager = (UsageStatsManager) context.getSystemService(Context.USAGE_STATS_SERVICE);

        long time = System.currentTimeMillis();

        UsageEvents usageEvents = mUsageStatsManager.queryEvents(time - 1000 * 30, System.currentTimeMillis() + (10 * 1000));
        UsageEvents.Event event = new UsageEvents.Event();
        String packageName = " ";
        while (usageEvents.hasNextEvent()) {
            usageEvents.getNextEvent(event);
            if (!TextUtils.isEmpty(event.getPackageName()) && event.getEventType() == UsageEvents.Event.MOVE_TO_FOREGROUND)
                packageName = event.getPackageName();
        }

        return packageName;
    }

    return " ";
}