ArcGISTiledMapServiceLayer's ServiceUri not binding to View Model's String Property

[RonVincent]

This is in regards to ArcGIS Runtime SDK for .NET (WPF) 10.2.6.. I have a ArcGISTiledMapServiceLayer and ArcGISDynamicMapServiceLayer that are attempting to get their ServiceUri from a string property on the View Model but it doesn't work. Other bindings work, even ones that are also string properties. ServiceUri is a string.

<esri:ArcGISTiledMapServiceLayer ID="Basemap"
          ServiceUri="{Binding Path=BasemapUri}"/>

<esri:ArcGISDynamicMapServiceLayer ID="USA" 
                         ServiceUri="{Binding USAUri}"/>

Any ideas as to why this would happen? I'm using MVVM Light. It's a string according to this:

ArcGISTiledMapServiceLayer.ServiceUri Property

Thanks,

Ron

[ThadTilton · Accepted solution]

Hi Ron -

The problem is that elements inside the MapView are not contained in the Page's control hierarchy. If you set a data context for the Page (or Window) it won't be available on things like Map and Layer. Since those things don't inherit from FrameworkElement, they won't be able to use the data context of elements that "contain" them.

If you define the data source explicitly with the binding, it should work as expected.

Here's an example of binding a layer's ServiceUri to a property in a ViewModel. The ViewModel has been defined as a static resource in App.xaml.

<esri:ArcGISTiledMapServiceLayer ID="Basemap"

ServiceUri="{Binding Source={StaticResource myVM}, Path=BaseMapUri}"/>

[RonVincent]

Thad,

Thanks for your reply. Once again you've helped me head down the right path with this. I had to do the following because of the Locator in MVVM Light:

<esri:ArcGISTiledMapServiceLayer ID="Basemap"

  ServiceUri="{Binding MainViewModel.BasemapUri, Source={StaticResource Locator}}"/>

Ron

[ThadTilton]

Awesome, glad you were able to crack it! Looks like MVVM Light adds an extra layer of complexity to the binding.

Thanks for posting your solution for others who will (inevitably) run into this problem.

Thad