/// <summary>
/// Called when the viewmodel request a view service.
/// </summary>
private void OnViewModel_ViewServiceRequest(object sender, ViewServiceRequestEventArgs e)
{
// Check for an implementation on the hosted control
if (TryFillViewServiceImplementation(m_host, e))
{
return;
}
// Try to walk the visual tree up until we find a view service implementation
DependencyObject actParent = VisualTreeHelper.GetParent(m_host);
FrameworkElement actParentElement = actParent as FrameworkElement;
while ((actParent != null) && (actParentElement == null))
{
if ((actParentElement != null) &&
(TryFillViewServiceImplementation(actParentElement, e)))
{
return;
}
actParent = VisualTreeHelper.GetParent(m_host);
actParentElement = actParent as FrameworkElement;
}
}
private bool TryFillViewServiceImplementation(FrameworkElement element, ViewServiceRequestEventArgs e)
{
ViewServiceCollection viewServices = element.GetValue(
Interaction.ViewServicesProperty) as ViewServiceCollection;
if (viewServices == null)
{
return(false);
}
// Try to find the view service within the host control
foreach (object actViewService in viewServices)
{
if (actViewService == null)
{
continue;
}
Type actViewServiceType = actViewService.GetType();
if (e.RequestedType.GetTypeInfo().IsAssignableFrom(actViewServiceType.GetTypeInfo()))
{
e.Implementation = actViewService;
return(true);
}
}
return(false);
}