問題描述

我正在獲取我最后一次知道的位置，但我不知道距離上次更新我的位置已有多長時間.我如何才能知道距離上次更新位置已有多長時間?

I am getting my last known location but not how long it has been since my location was last updated. How can I find out how long it has been since the location was last updated?

LocationManager locationManager 
                        = (LocationManager) getSystemService(LOCATION_SERVICE);
Criteria c = new Criteria();
    c.setAccuracy(Criteria.ACCURACY_FINE);
    c.setAccuracy(Criteria.ACCURACY_COARSE);
    c.setAltitudeRequired(false);
    c.setBearingRequired(false);
    c.setCostAllowed(true);
    c.setPowerRequirement(Criteria.POWER_HIGH);
String provider = locationManager.getBestProvider(c, true);
Location location = locationManager.getLastKnownLocation(provider);

推薦答案

API 17 前后的最佳選擇:

Best option for both pre and post API 17:

public int age_minutes(Location last) {
    return age_ms(last) / (60*1000);
}

public long age_ms(Location last) {
    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN_MR1)
        return age_ms_api_17(last);
    return age_ms_api_pre_17(last);
}

@TargetApi(Build.VERSION_CODES.JELLY_BEAN_MR1)
private long age_ms_api_17(Location last) {
    return (SystemClock.elapsedRealtimeNanos() - last
            .getElapsedRealtimeNanos()) / 1000000;
}

private long age_ms_api_pre_17(Location last) {
    return System.currentTimeMillis() - last.getTime();
}

pre 17 不是很準(zhǔn)確，但應(yīng)該足以測試一個位置是否很舊.

The pre 17 is not very accurate, but should be sufficient to test if a location is very old.

我認(rèn)為這樣就可以了:

if (age_minutes(lastLoc) < 5) {
   // fix is under 5 mins old, we'll use it

} else {
   // older than 5 mins, we'll ignore it and wait for new one

}

此邏輯的通常用例是應(yīng)用剛剛啟動時，我們需要知道我們是必須等待新位置還是在等待新位置時可以暫時使用最新位置位置.

The usual use case for this logic is when the app has just started and we need to know whether we must wait for a new location or can use the latest for now while we wait for a new location.

這篇關(guān)于最后一個已知位置是多久前記錄的?的文章就介紹到這了，希望我們推薦的答案對大家有所幫助，也希望大家多多支持html5模板網(wǎng)！