问题
I want to get a hard location fix every certain minutes & a soft location fix every certain minutes and if user has moved more then certain meters. I been testing the logic with following piece of code walking (tried it with larger parameters as well while driving) but it doesn't really return me periodic location fixes. It would return a location fix right away when request starts then sometime return 1 location fix few minutes later that but then for up-to an hour it won't return a location fix.
LocationRequest locationRequest = LocationRequest.create();
int priority = PRIORITY_BALANCED_POWER_ACCURACY;
locationRequest.setPriority(priority);
locationRequest.setInterval(localInterval); //set to 6 minutes
locationRequest.setFastestInterval(localFastestInterval); //set to 3 minutes
locationRequest.setSmallestDisplacement(smallestDisplacement); //set to 10 meters
locationRequest.setNumUpdates(numUpdates); //set to Int.MAX_VALUE
locationRequest.setExpirationDuration(expirationDuration); // set to Long.MAX_VALUE
LocationServices.FusedLocationApi.requestLocationUpdates(locationClient, locationRequest, pendingIntent);
If I set displacement to 0 then I get periodic location updates. Any idea what is going on?
回答1:
After long exhaustive testing & experimentation I've found that if you don't call setFastestInterval you will get periodic updates exactly according to the interval set with setInterval.
However as other applications can cause location fixes to be delivered very fast to you so just put a check for ignoring location fixes delivered faster than a certain threshold of time passed.
According to documentation: If setFastestInterval(long) is set slower than setInterval(long), then your effective fastest interval is setInterval(long) but that doesn’t happen: e.g. setting following parameters should give you a hard location fix every 1 minute but it does not (on Marshmallow at-least):
interval = 1 min
fastestInterval = 20 min
displacement = 0
If anyone can disprove my findings with a piece of code that would be great.
来源：https://stackoverflow.com/questions/39932475/android-fused-location-wont-deliver-periodic-updates