How to get usage stats for “current day” using usa

问题:

Objective:
Need to get the usage stats for today (total time for which the device was used today) ie. 12.00 am to current time.

Problem:
1.I get today's time + some other non explainable time
2.Non explainable time stamps(start and end of the usage stats as retrieved by the getTimestamp methods)
The time bucket is not relevant. I give the start time as 12.00 am and the end time as current time, but I get completely irrelevant ".firstTimeStamp" and ".lastTimeStamp" (which supposedly return the beginning and end of the usage stats data) for the usage statistics.

*already done the permission granting part, here is the function I'm using to get total time in minutes.

fun showtime(){

    val time=Calendar.getInstance()
    time.set(Calendar.HOUR_OF_DAY,0)
    time.set(Calendar.MINUTE,0)

    val start=time.timeInMillis
    val end= System.currentTimeMillis()

    val usageStatsManager = getSystemService(Context.USAGE_STATS_SERVICE) as UsageStatsManager
    var stats = usageStatsManager.queryAndAggregateUsageStats(start,end)

    var x:Long=0
    var ft:Long=0
    var v:Long=0
    var l:Long=0

    for ((key,value) in stats) {
        ft=value.totalTimeInForeground/60000
          textField1.append("$key = $ft mins")
            textField1.append("\n")
            x=x+ft
        v=value.firstTimeStamp
        l=value.lastTimeStamp
    }

    textView.setText("YOU SPENT $x mins.")
    textView2.setText("${Date(v)} to \n${Date(l)}")
}

As an example, when the above code runs at Wed 12 Dec 12.40 am, the result is:
(in textView):
YOU SPENT 90 mins
(in textView2):
Tue 11 Dec 16:23:19 GMT +05:30 2018 to
Tue 11 Dec 19:38:45 GMT +05:30 2018

How can I use my phone for 90 mins in just 40 mins?
And what does those apparently irrelevant timestamps mean?
Am I doing something wrong to achieve my objective?

回答1:

I actually experience a similar problem:

According to my understanding of the documentation firstTimeStamp and lastTimeStamp should give the "beginning (end) of the time range this UsageStats represents".

They differ however from what I give as an argument in queryAndAggregateUsageStats as beginTime and endTime.

Also the result for the totalTimeInForegroundseems rather give back a result for the timespan given by firstTimeStamp / lastTimeStamp than for the requested one.

I filled a bug with google for this, please have a look at https://issuetracker.google.com/issues/118564471.

回答2:

I noticed several problems with your approach.

• You are missing time.set(Calendar.SECOND,0) and time.set(Calendar.MILLISECOND,0)
• Precision is lost in the division ft=value.totalTimeInForeground/60000

I would recommend Java Time (ThreeTenBP) to handle DateTime and Duration more accurately. I create a new function to compare and indeed the results are different.

fun showtime2(){
    val start = LocalDate.now().atStartOfDay(ZoneId.systemDefault()).toInstant().toEpochMilli()
    val end = ZonedDateTime.now().toInstant().toEpochMilli()

    val usageStatsManager = getSystemService(Context.USAGE_STATS_SERVICE) as UsageStatsManager
    val stats = usageStatsManager.queryAndAggregateUsageStats(start, end)

    val total = Duration.ofMillis(stats.values.map { it.totalTimeInForeground }.sum())
    println("YOU SPENT ${total.toMinutes()} mins.")
}

Your output

YOU SPENT 577 mins.

My output

YOU SPENT 582 mins.