I thought that the visibility of the property associated with Layer.Visible map layer, but it turned out that it is associated with the property layerItemVM.IsEnabled. I solved the problem by replacing
[HTML]<CheckBox Content="{Binding Label}" IsChecked="{Binding IsEnabled, Mode=TwoWay}"/>[/HTML]
on this
[HTML]<CheckBox Content="{Binding Label}" IsChecked="{Binding Layer.Visible, Mode=TwoWay}"/>[/HTML]
in LayerItemTemplate:
[HTML]<DataTemplate x:Key="My_LayerTemplate">
<StackPanel Orientation="Horizontal">
<CheckBox Content="{Binding Label}" IsChecked="{Binding IsEnabled, Mode=TwoWay}"/>
</StackPanel>
</DataTemplate>[/HTML]
Can't anybody say where I can read about how layerItemVM.IsEnabled formed from the map layers properties?