private void ViewModelChanged(object sender, DependencyPropertyChangedEventArgs e)
        {
            this.InstExViewModel_ = this.DataContext as ExplorerBookInstViewModel;

            //ExplorerListView_.DataContext = InstExViewModel_;
            ExplorerListView_.ItemsSource = InstExViewModel_.InstHierarchyList_;
            OutputLogViewModel.addResult(new MessageOutput("ExplorerBookInstView : DataContext Changed"));
        }
        private void ViewModelChanged(object sender, DependencyPropertyChangedEventArgs e)
        {
            this.InstExViewModel_ = this.DataContext as ExplorerBookInstViewModel;

            //ExplorerListView_.DataContext = InstExViewModel_;
            ExplorerListView_.ItemsSource = InstExViewModel_.InstHierarchyList_;
            OutputLogViewModel.addResult(new MessageOutput("ExplorerBookInstView : DataContext Changed"));
        }