topic Re: Map becomes white when coming back clicking on Windows app top left back button in .NET Maps SDK Questions

Map becomes white when coming back clicking on Windows app top left back button

ErandaRanasinghe — Fri, 09 Feb 2018 03:25:54 GMT

Hi,

This app is Xamarin app developed using, Prism with DryIoc, and Syncfusion. This bug is in Windows version of the app (haven't tested on Android and iOS)

Once app opens, it loads with the map and loads the map points, then once map point is clicked, it opens a small pop up with some buttons. By clicking on one of the buttons it takes you to a new page. The issue happens when you coming back to the map and it is RANDOM (not always)

After days of investigating, I think that it is something related to the device's location. Once device's Location is turned off, it works fine. So I think it is related to two events, OnDrawStatusChanged and OnLocationChanged.

Once the location changes, it fires OnLocationChanged event and that cause to redraw the map (fires OnDrawStatusChanged event). Even you are sitting in the same location your location can be changed slightly. You can see the blue dot is slightly moving, every time blue dot moves it fires OnLocationChanged and then it fires OnDrawStatusChanged. When you coming back to map from using Windows App's back button also it calls OnDrawStatusChanged event. So if both these scenarios happened same time map becomes white. It is something like you coming back to the Map while it is being redrawn by location change event and it never gets to the Draw Status to Completed. Once device's location is turned off, it never fires OnLocationChanged event and map never gets white.

This video shows how it becomes white, wait until it gets to end.

https://1drv.ms/v/s!AjXE2HD7_LUvmSKL6iiZkG9O6CD-

I checked the project, but couldn't find any .net code which caused to redraw the map, it is mainly because of a slight location change.

Using ArcGIS Runtime SDK for .NET 100.2.0

Any clue or idea to solve this out?

Thanks a lot,

Re: Map becomes white when coming back clicking on Windows app top left back button

dotMorten_esri — Fri, 09 Feb 2018 17:07:04 GMT

We'll try and reproduce, but what happens if you turn locationdisplay off when leaving the page, and back on when coming back? Does that work around the issue?

(btw good-looking app!)

Re: Map becomes white when coming back clicking on Windows app top left back button

ErandaRanasinghe — Mon, 12 Feb 2018 01:37:11 GMT

Thank @Morten for your reply. I tried what you suggested, but now it gets the white screen much quicker than earlier ( just a couple of back and forths.) I disable LocationDisplay in OnNavigatedFrom and tried re-enabling it in both OnNavigatedTo and OnDrawStatusChanged event (if the status is Completed and if LocationDisplay is disabled). But it doesn't solve the issue. I noted it fires OnLocationChanged event twice as soon as I enabled LocationDisplay. (not sure why)

I guess if I click on the +WO button while map view's status is In Progress and come back to the map, it tries to make the status-completed and at the same time OnLocationChanged event calls OnDrawStatusChanged event and try to redraw the map.

(thanks, but having a real pain with this issue now)