TreeList.TopVisibleNodeIndex Property

Gets or sets the index of the top visible node.

Namespace: DevExpress.XtraTreeList

Assembly: DevExpress.XtraTreeList.v24.1.dll

NuGet Packages: DevExpress.Win.Navigation, DevExpress.Win.TreeList

Declaration

C#

[Browsable(false)]
public int TopVisibleNodeIndex { get; set; }

VB.NET

<Browsable(False)>
Public Property TopVisibleNodeIndex As Integer

Property Value

Type	Description
Int32	An integer value specifying the zero-based index of the top visible node.

Remarks

If the total node height exceeds the TreeList control’s client area, end-users can scroll the control’s contents vertically. You can use the TopVisibleNodeIndex property to obtain the index of the top visible node. Assigning a value to this property results in scrolling to the specified node. Note that if the specified node is hidden within the collapsed group, its closest visible parent becomes the topmost item.

Write a TreeList.TopVisibleNodeIndexChanged event handler to perform specific actions each time the control’s content is vertically scrolled.

Related GitHub Examples

The following code snippets (auto-collected from DevExpress Examples) contain references to the TopVisibleNodeIndex property.

Note

The algorithm used to collect these code examples remains a work in progress. Accordingly, the links and snippets below may produce inaccurate results. If you encounter an issue with code examples below, please use the feedback form on this page to report the issue.

C#

winforms-treelist-save-restore-expanded-state-of-nodes/CS/TreeListViewState.cs#L61

    if(topVisibleNode == null) topVisibleNode = TreeList.FocusedNode;
    TreeList.TopVisibleNodeIndex = TreeList.GetVisibleIndexByNode(topVisibleNode);
}

winforms-tokenedit-dropdown-with-treelist/CS/TokenEditTest/CustomTokenEditDropDownControl.cs#L62

    if(e.Delta > 0) step *= -1;
    TreeList.TopVisibleNodeIndex += step;
}

VB.NET

winforms-treelist-save-restore-expanded-state-of-nodes/VB/TreeListViewState.vb#L68

    End If
    TreeList.TopVisibleNodeIndex = TreeList.GetVisibleIndexByNode(topVisibleNode)
End Try

winforms-tokenedit-dropdown-with-treelist/VB/TokenEditTest/CustomTokenEditDropDownControl.vb#L70

    End If
    TreeList.TopVisibleNodeIndex += [step]
End Sub