`et`的Android.Location.toString()解释

Question

当我在 Location 对象上使用 .toString() 方法时，我得到如下结果:

Location[gps 01.234567,12.234567 
         acc=14 
         et=+2d23h36m34s870ms 
         alt=123.0 
         vel=0.0 
         {Bundle[mParcelledData.dataSize=40]}
         ]

(我添加了换行符以提高可读性)

我猜(经过这里的一些研究:link):

• acc=14 是以米为单位的精度
• vel=0 是以米/秒为单位的速度
• alt=123 是 WGS 引用椭球上方的高度(以米为单位)

---

但是 et=+2d23h36m34s870ms 是什么？

Answer 1

根据 javadocs:

/** * Return the time of this fix, in elapsed real-time since system boot. * *

This value can be reliably compared to * {@link android.os.SystemClock#elapsedRealtimeNanos}, * to calculate the age of a fix and to compare Location fixes. This * is reliable because elapsed real-time is guaranteed monotonic for * each system boot and continues to increment even when the system * is in deep sleep (unlike {@link #getTime}. * *

All locations generated by the {@link LocationManager} * are guaranteed to have a valid elapsed real-time. * * @return elapsed real-time of fix, in nanoseconds since system boot. */

public long getElapsedRealtimeNanos() {
    return mElapsedRealtimeNanos;
}

toString 与et

相关的代码

if (mElapsedRealtimeNanos == 0) {
    s.append(" et=?!?");
} else {
    s.append(" et=");
    TimeUtils.formatDuration(mElapsedRealtimeNanos / 1000000L, s);
}

顺便说一句，它的意思可能是自上次更新位置以来已经过了多长时间