问题：
尽快使用户的当前位置在阈值之内，同时节省电池。
为什么问题是一个问题：
首先，android有两个提供程序；网络和GPS。有时网络会更好，有时GPS会更好。
“更好”是指速度与精度之比。
如果我几乎可以立即获得位置信息而无需打开GPS，则我愿意牺牲几米的精度。
其次，如果您请求位置更改的更新，并且当前位置稳定，则不会发送任何内容。
Google提供了一个确定“最佳”位置的示例：http : //developer.android.com/guide/topics/location/obtaining-user-location.html#BestEstimate
但我认为这没有应该做的那么好/可能。
我有点困惑，为什么google没有用于位置的标准化API，开发人员不必关心位置的来源，您只需指定所需的内容，然后电话为您选择。
我需要什么帮助：
我需要找到一种确定“最佳”位置的好方法，也许是通过某种启发式方法，或者通过一些第三方库。
这并不意味着确定最佳提供商！
我可能会使用所有提供商，并从中选择最好的提供商。
应用程序的背景：
该应用程序将以固定的时间间隔（假设每10分钟左右）收集用户的位置，并将其发送到服务器。
该应用程序应尽可能节省电池，并且该位置的精度应为X（50-100？）米。
目标是以后能够在一天中在地图上绘制用户的路径，因此我需要足够的准确性。
其他：
您认为期望和接受的精度的合理值是多少？
我一直在使用100m作为可接受的值，并根据需要使用30m，这是个要问的问题吗？
我希望以后能够在地图上绘制用户的路径。
理想的100m和可接受的500m是否更好？
另外，现在我在每次位置更新中最多打开GPS 60秒，如果您在室内，精度可能达到200m，这太短了，无法找到位置吗？
这是我当前的代码，感谢任何反馈（除了缺少错误检查（TODO））：
protected void runTask() {
final LocationManager locationManager = (LocationManager) context
.getSystemService(Context.LOCATION_SERVICE);
updateBestLocation(locationManager
.getLastKnownLocation(LocationManager.GPS_PROVIDER));
updateBestLocation(locationManager
.getLastKnownLocation(LocationManager.NETWORK_PROVIDER));
if (getLocationQuality(bestLocation) != LocationQuality.GOOD) {
Looper.prepare();
setLooper(Looper.myLooper());
// Define a listener that responds to location updates
LocationListener locationListener = new LocationListener() {
public void onLocationChanged(Location location) {
updateBestLocation(location);
if (getLocationQuality(bestLocation) != LocationQuality.GOOD)
return;
// We're done
Looper l = getLooper();
if (l != null) l.quit();
}
public void onProviderEnabled(String provider) {}
public void onProviderDisabled(String provider) {}
public void onStatusChanged(String provider, int status,
Bundle extras) {
// TODO Auto-generated method stub
Log.i("LocationCollector", "Fail");
Looper l = getLooper();
if (l != null) l.quit();
}
};
// Register the listener with the Location Manager to receive
// location updates
locationManager.requestLocationUpdates(
LocationManager.GPS_PROVIDER, 1000, 1, locationListener,
Looper.myLooper());
locationManager.requestLocationUpdates(
LocationManager.NETWORK_PROVIDER, 1000, 1,
locationListener, Looper.myLooper());
Timer t = new Timer();
t.schedule(new TimerTask() {
@Override
public void run() {
Looper l = getLooper();
if (l != null) l.quit();
// Log.i("LocationCollector",
// "Stopping collector due to timeout");
}
}, MAX_POLLING_TIME);
Looper.loop();
t.cancel();
locationManager.removeUpdates(locationListener);
setLooper(null);
}
if (getLocationQuality(bestLocation) != LocationQuality.BAD)
sendUpdate(locationToString(bestLocation));
else Log.w("LocationCollector", "Failed to get a location");
}
private enum LocationQuality {
BAD, ACCEPTED, GOOD;
public String toString() {
if (this == GOOD) return "Good";
else if (this == ACCEPTED) return "Accepted";
else return "Bad";
}
}
private LocationQuality getLocationQuality(Location location) {
if (location == null) return LocationQuality.BAD;
if (!location.hasAccuracy()) return LocationQuality.BAD;
long currentTime = System.currentTimeMillis();
if (currentTime - location.getTime() < MAX_AGE
&& location.getAccuracy() <= GOOD_ACCURACY)
return LocationQuality.GOOD;
if (location.getAccuracy() <= ACCEPTED_ACCURACY)
return LocationQuality.ACCEPTED;
return LocationQuality.BAD;
}
private synchronized void updateBestLocation(Location location) {
bestLocation = getBestLocation(location, bestLocation);
}
// Pretty much an unmodified version of googles example
protected Location getBestLocation(Location location,
Location currentBestLocation) {
if (currentBestLocation == null) {
// A new location is always better than no location
return location;
}
if (location == null) return currentBestLocation;
// Check whether the new location fix is newer or older
long timeDelta = location.getTime() - currentBestLocation.getTime();
boolean isSignificantlyNewer = timeDelta > TWO_MINUTES;
boolean isSignificantlyOlder = timeDelta < -TWO_MINUTES;
boolean isNewer = timeDelta > 0;
// If it's been more than two minutes since the current location, use
// the new location
// because the user has likely moved
if (isSignificantlyNewer) {
return location;
// If the new location is more than two minutes older, it must be
// worse
} else if (isSignificantlyOlder) {
return currentBestLocation;
}
// Check whether the new location fix is more or less accurate
int accuracyDelta = (int) (location.getAccuracy() - currentBestLocation
.getAccuracy());
boolean isLessAccurate = accuracyDelta > 0;
boolean isMoreAccurate = accuracyDelta < 0;
boolean isSignificantlyLessAccurate = accuracyDelta > 200;
// Check if the old and new location are from the same provider
boolean isFromSameProvider = isSameProvider(location.getProvider(),
currentBestLocation.getProvider());
// Determine location quality using a combination of timeliness and
// accuracy
if (isMoreAccurate) {
return location;
} else if (isNewer && !isLessAccurate) {
return location;
} else if (isNewer && !isSignificantlyLessAccurate
&& isFromSameProvider) {
return location;
}
return bestLocation;
}
/** Checks whether two providers are the same */
private boolean isSameProvider(String provider1, String provider2) {
if (provider1 == null) {
return provider2 == null;
}
return provider1.equals(provider2);
}
7
鸣叫确实很晚，但是最近在IO 2013上宣布的“融合位置提供者”似乎可以满足您的许多需求-developer.android.com/google/play-services/location.html
—
Matt
getBestLocation（）的最后一行不应该是：return currentBestLocation; 而不是返回bestLocation ;？
—
加夫里尔2015年