100.1 External GPS Quirk

Question

Not all of my Runtime users have internal GPS yet, and while porting my serial GPS code from 10.2.7 to 100.1, I've noticed an odd quirk. When the location display is first enabled by the application, it doesn't always display the valid locations coming in. Disabling and re-enabling fixes the problem, so as a workaround I added this snippet after the first valid point is collected and sent to the display: _ld.IsEnabled = false; Thread.Sleep(100); _ld.IsEnabled = true; ‍‍‍ Has anyone else seen this?

MarkCederholm · Answer

Looks like one workaround is to set the velocity to a non-zero number (e.g. 0.1).  Of course, that affects which symbol is displayed.  [If I set UseCourseSymbolOnMovement to false, the problem persists.]

MarkCederholm · Answer

I was able to duplicate the problem with your example by setting AutoPan to "Recenter" and horizontal accuracy, speed, and course all to 0.

MarkCederholm · Answer

I use tasks to help keep the app from locking.  Good call on LocationChanged -- I was still thinking in terms of ILocationProvider.  Even after renaming it, though, the point display problem persists.

Re your example, I tracked it to horizontal accuracy is NaN, which the location constructor doesn't accept.  I ran into that problem myself, and substitute 0 on those occasions.  I updated the example on my end and it works now.