I would like to implement MapScale control as it done in arcgis Desktop.
I put on View ComboBox , bind SelectedValue of ComboBox to SelectedMapScale in MapViewModel.
In arcObjects I did this as follows:
axMapControl1.MapScale = SelectedMapScale ;
How to set the desired map scale with arcgis API for WPF?
I found experimentally approximate coefficient connecting resolution and MapScale. Thus, when SelectedMapScale changed I do the following operations:
Map.ZoomToResolution( SelectedMapScale * 0.0002644, mapPoint);