title: Android Location service didn't work in background
body: <p>I am working on a Location-App which should begin to track some statistic data based on longitude and latitude when the user presses a <code>Button</code>. All this stuff works very well but when it comes to lock the screen or put the app in the background the service does not work anymore ! </p>
  
  <p>I have read a lot about background services and Broadcast receivers but I don't know how to implement the Google API Location listener in a Service and where to implement this class in the <code>MainActivity</code>. Can anyone tell me with a short code example how to implement such a service or a link where this is explained ? </p>