我需要接收来自网络和 GPS 提供商的位置更改。
如果 GPS 供应商不可用或没有位置(卫星能见度差),我会从网络供应商那里收到位置信息,或者从 GPS 供应商那里获得位置信息。
是否可以根据我的需要使用标准选择提供者?
我需要接收来自网络和 GPS 提供商的位置更改。
如果 GPS 供应商不可用或没有位置(卫星能见度差),我会从网络供应商那里收到位置信息,或者从 GPS 供应商那里获得位置信息。
是否可以根据我的需要使用标准选择提供者?
实际上,Android Developers - Making Your App Location Aware有一个很好的示例代码可以满足您的需求。
在其代码中,如果您同时使用这两个提供商(来自 GPS 和来自网络),它将进行比较:
...
} else if (mUseBoth) {
// Get coarse and fine location updates.
mFineProviderButton.setBackgroundResource(R.drawable.button_inactive);
mBothProviderButton.setBackgroundResource(R.drawable.button_active);
// Request updates from both fine (gps) and coarse (network) providers.
gpsLocation = requestUpdatesFromProvider(
LocationManager.GPS_PROVIDER, R.string.not_support_gps);
networkLocation = requestUpdatesFromProvider(
LocationManager.NETWORK_PROVIDER, R.string.not_support_network);
// If both providers return last known locations, compare the two and use the better
// one to update the UI. If only one provider returns a location, use it.
if (gpsLocation != null && networkLocation != null) {
updateUILocation(getBetterLocation(gpsLocation, networkLocation));
} else if (gpsLocation != null) {
updateUILocation(gpsLocation);
} else if (networkLocation != null) {
updateUILocation(networkLocation);
}
}
...
它实现了最佳位置提供者的想法(通过确定指定时间段内的准确性,例如:
/** Determines whether one Location reading is better than the current Location fix.
* Code taken from
* http://developer.android.com/guide/topics/location/obtaining-user-location.html
*
* @param newLocation The new Location that you want to evaluate
* @param currentBestLocation The current Location fix, to which you want to compare the new
* one
* @return The better Location object based on recency and accuracy.
*/
protected Location getBetterLocation(Location newLocation, Location currentBestLocation) {
if (currentBestLocation == null) {
// A new location is always better than no location
return newLocation;
}
// Check whether the new location fix is newer or older
long timeDelta = newLocation.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 newLocation;
// 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) (newLocation.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(newLocation.getProvider(),
currentBestLocation.getProvider());
// Determine location quality using a combination of timeliness and accuracy
if (isMoreAccurate) {
return newLocation;
} else if (isNewer && !isLessAccurate) {
return newLocation;
} else if (isNewer && !isSignificantlyLessAccurate && isFromSameProvider) {
return newLocation;
}
return currentBestLocation;
}
有关完整代码,请查看上面提供的链接。
对于搜索最佳位置提供商,请使用以下代码:请参阅https://developer.android.com/reference/android/location/Criteria.html 了解,标准将如何工作?
public String getProviderName() {
LocationManager locationManager =(LocationManager)this.getSystemService(Context.LOCATION_SERVICE);
Criteria criteria = new Criteria();
criteria.setPowerRequirement(Criteria.POWER_LOW);
criteria.setAccuracy(Criteria.ACCURACY_FINE);
criteria.setSpeedRequired(true);
criteria.setAltitudeRequired(false);
criteria.setBearingRequired(false);
criteria.setCostAllowed(false);
return locationManager.getBestProvider(criteria, true);
}
只是不给出任何标准,并尝试获得最好的提供者:
LocationManager mgr = (LocationManager) getSystemService(LOCATION_SERVICE);
Criteria criteria = new Criteria();
String best = mgr.getBestProvider(criteria, true);
//since you are using true as the second parameter, you will only get the best of providers which are enabled.
Location location = mgr.getLastKnownLocation(best);