正如您在Google http://developer.android.com/guide/topics/location/strategies.html的位置策略页面中所看到的,该位置一旦读取就会存储在缓存中(附快速参考图片)
正如您所看到的,位置已缓存,因为它太旧而被解雇。我不想使用这个缓存。如何禁用它以便每次谷歌收听和检索新鲜的位置(我不关心电池只关心更准确的位置)
答案 0 :(得分:1)
将您以前的位置与onLocationChanged()方法中的新位置进行比较,如下所示:
Location prevLocation=null;
private static final int TWO_MINUTES = 1000 * 60 * 2; // time difference between location updates
// Define a listener that responds to location updates
LocationListener locationListener = new LocationListener() {
//calls everytime when new location updates found
public void onLocationChanged(Location location) {
// Called when a new location is found by the network location provider.
if(isBetterLocation(location, getPrevLocation())){
// write your logic to use of new location
// set your new location to prevlocation
setPrevLocation(location);
}
}
public void onStatusChanged(String provider, int status, Bundle extras) {}
public void onProviderEnabled(String provider) {}
public void onProviderDisabled(String provider) {}
};
/** Determines whether one Location reading is better than the current Location fix
* @param location The new Location that you want to evaluate
* @param currentBestLocation The current Location fix, to which you want to compare the new one
*/
protected boolean isBetterLocation(Location location, Location currentBestLocation) {
if (currentBestLocation == null) {
// A new location is always better than no location
return true;
}
// 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 true;
// If the new location is more than two minutes older, it must be worse
} else if (isSignificantlyOlder) {
return false;
}
// 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 true;
} else if (isNewer && !isLessAccurate) {
return true;
} else if (isNewer && !isSignificantlyLessAccurate && isFromSameProvider) {
return true;
}
return false;
}
/** Checks whether two providers are the same */
private boolean isSameProvider(String provider1, String provider2) {
if (provider1 == null) {
return provider2 == null;
}
return provider1.equals(provider2);
}
public void setPrevLocation(Location prevLocation){
this.prevLocation=prevLocation;
}
public Location getPrevLocation(){
return prevLocation;
}