private void ExecuteOpenHighlightCommand(object obj) { var dialog = _dialogFactory.GetHighlightDialog(); var vm = dialog.DataContext as IHighlightDialogViewModel; vm.HighlightColorChanged += Vm_HighlightColorChanged; dialog.ShowModal(); vm.HighlightColorChanged -= Vm_HighlightColorChanged; _documentPanelViewModel.InvalidateAllPageGrids(); }