Using keyboard to expand nodes

[Craig Greenway]

Hi, I was surprised that the GridTree didn't expand nodes when pressing the Right arrow key on the keyboard.  I was happy with the keyboard behaviour for up and down to move between expanded nodes only, but I can't see any instructions on how to expand nodes using the keyboard.  Please could you point me in the right direction?

[Jai Ganesh S]

Hi Craig, 

 

You can achieve your requirement by using the PreviewKeydown event like below, 

 

treeGrid.PreviewKeyDown += treeGrid_PreviewKeyDown; 

 

void treeGrid_PreviewKeyDown(object sender, KeyEventArgs e) 

  { 

            var node = this.treeGrid.SelectedNode as GridTreeNode; 

 

            if (node == null) 

                return; 

 

            if (node.ParentNode == null && e.Key == Key.Right) 

            { 

                treeGrid.InternalGrid.ExpandNode(node); 

                 

                e.Handled = true; 

            } 

            else if (node.ParentNode == null && e.Key == Key.Left) 

            { 

                treeGrid.InternalGrid.CollapseNode(node); 

            } 

 

            treeGrid.InternalGrid.ResetDisplay(); 

 

   } 

 

Sample: http://www.syncfusion.com/downloads/support/directtrac/156529/ze/Cell_Editors_Demo231451914 

 

Regards, 

Jai Ganesh S 

[Craig Greenway]

Thank you, if you have a few levels of nodes, rather than checking ParentNode is there a HasChildren or similar property?

[Craig Greenway]

Thank you, if you have a few levels of nodes, rather than checking ParentNode is there a HasChildren or similar property?

Sorry found what I needed, here's my code for other people:

        private void treeGrid_OnPreviewKeyDown(object sender, KeyEventArgs e)
        {
            var node = this.treeGrid.SelectedNode as GridTreeNode;
           
            if (node == null)
                return;       

            if (node.HasChildNodes && e.Key == Key.Right)
            {
                treeGrid.InternalGrid.ExpandNode(node);
                e.Handled = true;
            }
            else if (node.HasChildNodes && e.Key == Key.Left)
            {
                treeGrid.InternalGrid.CollapseNode(node);
                e.Handled = true;
            }
            else if (e.Key == Key.Right || e.Key == Key.Left)
            {
                e.Handled = true;
            }

            treeGrid.InternalGrid.ResetDisplay();
        }

[Jai Ganesh S]

Hi Craig, 

 

Thank you for the update. 

 

Please let us know if you need further assistance on this. 

 

Regards, 

Jai Ganesh S