You are getting the null pointer b/c getLastKnownLocation has nothing to give... In this case you would need to call up the GPS listener... When it gets the current fix it will pop off its subroutine.. Inside there you can get the lat/lon do what you need to do with your button click then kill the GPS listener..
-----Original Message----- From: android-developers@googlegroups.com [mailto:android-developers@googlegroups.com] On Behalf Of Mark Murphy Sent: Thursday, May 05, 2011 3:29 PM To: android-developers@googlegroups.com Subject: Re: [android-developers] Re: Android app crashes when invoking getSystemService(LOCATION_SERVICE) requestLocationUpdates() is asynchronous. It may take seconds or more for the location to be determined, depending on the location provider being used and the user's circumstances (e.g., is the user getting a GPS signal?). You cannot simply call getLastKnownLocation() immediately after calling requestLocationUpdates() and expect to get any value. Your whole premise (press a button, get a location) will only work if either: 1. You have location updates started early (e.g., onResume()), so by the time the user presses the button, you probably have a fix, or 2. Pressing the button triggers the request for the location, and it simply does not have an immediate effect, until the fix arrives On Thu, May 5, 2011 at 3:23 PM, Prayag Pathak <prayag.d.pat...@gmail.com> wrote: > Hi Mark, > > Thanks for the answer. But still its not working. I included the code > segment that updates the code. But still not working. > Following is the code : > > LocationManager lm = (LocationManager) > getSystemService(Context.LOCATION_SERVICE); > LocationListener ll = new mylocationlistener(); > lm.requestLocationUpdates(LocationManager.GPS_PROVIDER, 0, 0, > ll); > Location l = > lm.getLastKnownLocation(lm.getProvider(LOCATION_SERVICE).getName()); > Log.w("LocationTracker", "The value of Location returned by > getLastKnownLocation() is : " + l.toString()); > Log.d("Current Location", l.getLatitude() + ""); > Log.d("Current Location",l.getLongitude() + ""); > Toast.makeText(this, l.getLatitude() + "" + > l.getLongitude(),Toast.LENGTH_LONG).show(); > > Regards, > > Prayag > > On May 5, 2:20 pm, Prayag Pathak <prayag.d.pat...@gmail.com> wrote: >> Hi guys, >> >> I am trying to get the latitude and longitude of the current location. >> Let me clarify, I dont want to implement a listener that will create >> an event when the location will be changed. I am trying to create an >> app that will record the current location on a button click event. >> Following is my code : >> >> hdLocMgr = (LocationManager) >> getSystemService(Context.LOCATION_SERVICE); >> Log.w("LocationTracker", "The Location Manager is : >> "+hdLocMgr.toString()); >> hdLocProvider = hdLocMgr.getBestProvider(hdCrit, true); location = >> hdLocMgr.getLastKnownLocation(hdLocProvider); >> dlat = location.getLatitude(); >> dlon = location.getLongitude(); >> Log.w("LocationTracker", "The value of Latitude is : >> "+dlat.toString()); >> >> The code gives a RunTimeException (caused by NullPointerException as >> stated in it). >> >> Kindly help me out in that. >> >> Regards, >> >> Prayag > > -- > You received this message because you are subscribed to the Google > Groups "Android Developers" group. > To post to this group, send email to > android-developers@googlegroups.com > To unsubscribe from this group, send email to > android-developers+unsubscr...@googlegroups.com > For more options, visit this group at > http://groups.google.com/group/android-developers?hl=en > -- Mark Murphy (a Commons Guy) http://commonsware.com | http://github.com/commonsguy http://commonsware.com/blog | http://twitter.com/commonsguy _Android Programming Tutorials_ Version 3.4 Available! -- You received this message because you are subscribed to the Google Groups "Android Developers" group. To post to this group, send email to android-developers@googlegroups.com To unsubscribe from this group, send email to android-developers+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/android-developers?hl=en -- You received this message because you are subscribed to the Google Groups "Android Developers" group. To post to this group, send email to android-developers@googlegroups.com To unsubscribe from this group, send email to android-developers+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/android-developers?hl=en
