Android 抓取 App 使用时长大致分为4个步骤

1. 申明权限

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    package="com.xx.yy">
    <uses-permission android:name="android.permission.PACKAGE_USAGE_STATS" tools:ignore="ProtectedPermissions" />
</manifest>

2. 检查权限

因为该权限非常规权限，处理方式稍有不同

fun checkHasAppUsagePermission(context: Context?): Boolean {
    var granted = false
    if (context != null && Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
        try {
            val appOps = context.getSystemService(Context.APP_OPS_SERVICE) as AppOpsManager
            val mode = appOps.checkOpNoThrow(
                AppOpsManager.OPSTR_GET_USAGE_STATS,
                Process.myUid(),
                context.packageName
            )
            granted = if (mode == AppOpsManager.MODE_DEFAULT) {
                val permissionUsage = "android.permission.PACKAGE_USAGE_STATS"
                context.checkCallingOrSelfPermission(permissionUsage) == PackageManager.PERMISSION_GRANTED
            } else {
                mode == AppOpsManager.MODE_ALLOWED
            }
        } catch (e: Throwable) {
        }
    }
    return granted
}

3. 打开权限

引导用户去设置页面打开权限

fun openPkgUsagePermission(context: Context?) {
    if (context != null && Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
        val intent = getIntent(context)
        intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK)
        try {
            context.startActivity(intent)
        } catch (e: Exception) {
            e.printStackTrace()
        }
    }
}

4. 获取App使用时长

@TargetApi(Build.VERSION_CODES.LOLLIPOP)
fun getPackageUsageStatsDatas(context: Context): List<UsageStats>? {
    return if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
        val calendar = Calendar.getInstance()
        calendar.time = Date() 
        //完毕时刻
        val endt = calendar.timeInMillis
        //时刻间隔为两年
        calendar.add(Calendar.DAY_OF_YEAR, -2)
        //开端时刻
        val statt = calendar.timeInMillis
        val usageStatsManager =
            context.getSystemService(Context.USAGE_STATS_SERVICE) as UsageStatsManager
        var queryUsageStats: List<UsageStats>? = null
        try {
            queryUsageStats = usageStatsManager.queryUsageStats(
                UsageStatsManager.INTERVAL_YEARLY,
                statt,
                endt
            )
        } catch (ignore: Throwable) {}
        queryUsageStats
    } else {
        null
    }
}