UsageStatsManager从最后一天/周/月/年返回数据？

Question

我想查询UsageStats从UsageStatsManager.我已经建立了一个DateUtils课程,为我提供了获取每天/每月/每年(一周即将到来)的开始和结束时间的方法,如下所示:

public static Calendar getCal(int year, int month, int day) {
    Calendar cal = Calendar.getInstance();
    cal.set(year, month, day, 0, 0, 0);
    cal.set(Calendar.MILLISECOND, 0);
    return cal;
}

public static long getDayStart(int year, int month, int day) {
    return getCal(year, month, day).getTimeInMillis();
}

public static long getDayEnd(int year, int month, int day) {
    Calendar cal = getCal(year, month, day);
    cal.add(Calendar.DATE, 1);
    return cal.getTimeInMillis();
}

我正在使用这些长篇来查询UsageStats不同的日子:

 mUsageStats = mUsageStatsManager.queryUsageStats(UsageStatsManager.INTERVAL_DAILY, startTime, endTime);

我今天可以获取数据,但前几天将返回一个空列表.

这是我用来获取数据的方法:

12 nov 2014, with type UsageStatsManager.INTERVAL_DAILY
startTime: 1415746800000
endTime: 1415833200000
mUsageStats size: 18

11 nov 2014, with type UsageStatsManager.INTERVAL_DAILY
startTime: 1415660400000
endTime: 1415746800000
mUsageStats size: 0

API中是否存在限制,导致我无法获取旧数据或者我做错了什么？

Answer 1

您可以使用具有正确毫秒数的方法，从您想要的任何日期（在此处设置的范围内）获取使用情况统计信息，queryAndAggregateUsageStats()如下所示：

UsageStatsManager mUsageStatsManager = (UsageStatsManager) getSystemService(Context.USAGE_STATS_SERVICE);
if(mUsageStatsManager != null){
    Calendar beginCal = Calendar.getInstance();
    beginCal.add(Calendar.DATE, -1); // get yesterdays data
    Calendar  endCal = Calendar.getInstance();

    Map<String, UsageStats> queryUsageStats = mUsageStatsManager.queryAndAggregateUsageStats(beginCal.getTimeInMillis(), endCal.getTimeInMillis());
}