C# .NET - How to run Location background task long time in Xamarin.Forms

Asked By Nguyen Liem on 26-Apr-17 05:43 AM
Hi everybody!
I'm working with an app to calculate distance using GPS in Xamarin.Forms.
I have 2 button in a View of Portable project: 1 START and 1 STOP
How to run location background task when I tap START button. And it's only stop when I tap STOP button?
Thank you!