Binding element visibility to a ViewModel property, with design-time support
caliburn.micro, fody-propertychanged, wpf
Solution
You can set a `FallbackValue` on your binding, that will `Collapse` it in design time
Visibility="{Binding IsWaiting, Converter={StaticResource BooleanToVisibilityConverter}, FallbackValue=Collapsed}"
You could also make `IsWaiting` a `DependancyProperty` and set the default there, But I find this the easiest solution.
Problem
I've got a WPF application using Caliburn.Micro. I want to be able to overlay the application with a shadow and progress ring (from MahApps.Metro) when I want the application to wait for some work to be done in the background. What I have at the moment actually works but the overlay is always-on at design time. My `ShellView` window looks like this: ``` <Window ...> ... <Grid> ... <Rectangle x:Name="waitShadow" Fill="#3f000000" Stroke="Black" StrokeThickness="0" Visibility="{Binding IsWaiting, Converter={StaticResource BooleanToVisibilityConverter}}" Grid.RowSpan="2"/> <ContentControl ... Visibility="{Binding IsWaiting, Converter={StaticResource BooleanToVisibilityConverter}}"> <Controls:ProgressRing ...> <!-- from MahApps.Metro --> </Controls:ProgressRing> </ContentControl> </Grid> </Window> ``` My `ShellViewModel` class has a public bool property `IsWaiting` and when I set it to `true` the shadow and ring comes up and everything is disabled. When I set it to `false` it goes back to normal, so the binding works (I'm using Fody with the PropertyChanged addin). The only problem is that the `Visibility` property isn't collapsed at design time. Is there a better way to have an overlay that works at design time?