TreeList.TopVisibleNodeIndex Property

Gets or sets the index of the top visible node.

Namespace: DevExpress.XtraTreeList

Assembly: DevExpress.XtraTreeList.v19.2.dll

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#

how-to-preserve-the-expanded-state-of-treelist-nodes-when-refreshing-data-e864/CS/TreeListViewState.cs#L61

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

how-to-show-a-tooltip-while-scrolling-the-treelist-e202/CS/Form1.cs#L32

    if (MouseButtons == MouseButtons.Left)
        e.Info = new DevExpress.Utils.ToolTipControlInfo(treeList1.TopVisibleNodeIndex, treeList1.TopVisibleNodeIndex.ToString(), true, DevExpress.Utils.ToolTipIconType.None);
}

how-to-scroll-the-treelist-programmatically-e645/CS/Form1.cs#L121

private void simpleButton1_Click(object sender, System.EventArgs e) {
    treeList1.TopVisibleNodeIndex += 1;
}

how-to-navigate-to-the-last-summary-using-keyboard-navigation-e379/CS/WindowsApplication255/Form1.cs#L30

    if (treeList1.FocusedNode == last && last.NextVisibleNode == null)
        treeList1.TopVisibleNodeIndex = treeList1.GetVisibleIndexByNode(ri.Node);
}

how-to-set-a-treelist-as-a-custom-drop-down-for-the-tokenedit-t163562/CS/TokenEditTest/CustomTokenEditDropDownControl.cs#L62

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

VB.NET

how-to-show-a-tooltip-while-scrolling-the-treelist-e202/VB/Form1.vb#L29

If MouseButtons = MouseButtons.Left Then
    e.Info = New DevExpress.Utils.ToolTipControlInfo(treeList1.TopVisibleNodeIndex, treeList1.TopVisibleNodeIndex.ToString(), True, DevExpress.Utils.ToolTipIconType.None)
End If

how-to-scroll-the-treelist-programmatically-e645/VB/Form1.vb#L115

Private Sub simpleButton1_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles simpleButton1.Click
    treeList1.TopVisibleNodeIndex += 1
End Sub

how-to-preserve-the-expanded-state-of-treelist-nodes-when-refreshing-data-e864/VB/TreeListViewState.vb#L76

    focused = TreeList.FocusedNode(TreeList.KeyFieldName)
    topNode = TreeList.GetNodeByVisibleIndex(TreeList.TopVisibleNodeIndex)(TreeList.KeyFieldName)
Else

how-to-navigate-to-the-last-summary-using-keyboard-navigation-e379/VB/WindowsApplication255/Form1.vb#L27

If treeList1.FocusedNode Is last AndAlso last.NextVisibleNode Is Nothing Then
    treeList1.TopVisibleNodeIndex = treeList1.GetVisibleIndexByNode(ri.Node)
End If

how-to-set-a-treelist-as-a-custom-drop-down-for-the-tokenedit-t163562/VB/TokenEditTest/CustomTokenEditDropDownControl.vb#L70

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