topic MVVM for Graphics Overlays in .NET Maps SDK Questions

MVVM for Graphics Overlays

CharlesRoberts1 — Sat, 08 Dec 2018 19:57:09 GMT

Most WPF .Net 100.X samples use a Static Resource of the Map object declared in the xaml file. Then the Map property of the MapView control is set to Static Resource instance. I would like to do the same for Graphics overlays but this does not seem to be possible. The exposed Overlays property is for an unrelated Items control. Sure, I can use the somewhat confusing approach as is demonstrated in the "Controller" samples (demonstrates injecting a "weak" reference to the MapView into the view model to control, for example, the map viewpoint from the ViewModel), but is there no more straight forward way?

Re: MVVM for Graphics Overlays

dotMorten_esri — Mon, 10 Dec 2018 17:55:13 GMT

The approach I'd suggest is you create a view model that contains both a Map and a GraphicsOverlayCollection, then set the datacontext to that viewmodel. Then you'll merely bind the two to the mapview:

<esri:MapView Map="{Binding Map}" GraphicsOverlays="{Binding Overlays}" />

Re: MVVM for Graphics Overlays

CharlesRoberts1 — Mon, 10 Dec 2018 18:12:26 GMT

Ah, of course. I was thrown off by the Overlays property and did not notice GraphicsOverlays.

Thank you for steering me in the right direction.