private static object OnCoerceGroupChanged(DependencyObject o, object newValue)
{
ForeignKeyGroupContentControl contentControl = o as ForeignKeyGroupContentControl;
if (contentControl != null)
{
Group currentGroup = contentControl.Group;
Group newGroup = newValue as Group;
bool clearContentTemplate = false;
if ((currentGroup != null) && (newGroup != null))
{
if ((currentGroup.Level == -1) || (newGroup.Level == -1))
{
clearContentTemplate = true;
}
// The Group is different, must clear the templates
else if (currentGroup.GroupBy != newGroup.GroupBy)
{
clearContentTemplate = true;
}
}
else
{
// The Group is null or different, must clear the templates
clearContentTemplate = true;
}
if (clearContentTemplate)
{
contentControl.ClearValue(ContentControl.ContentTemplateProperty);
contentControl.ClearValue(ContentControl.ContentTemplateSelectorProperty);
}
}
return(newValue);
}