Export To Excel in WPF TreeGrid (SfTreeGrid)

2 Aug 202324 minutes to read

SfTreeGrid provides support to export the data to Excel file. This also provides support to export the headers and stacked headers. This maintains the sorting and filtering processes when exporting.

The following assemblies should be added for exporting a tree grid to Excel:-

  • Syncfusion.SfGridConverter.WPF
  • Syncfusion.XlsIO.Base
  • Syncfusion.XlsIO.Wpf

For NuGet package, have to install Syncfusion.DataGridExcelExport.WPF package. For more details refer this UG link.

You can export the tree grid to Excel by using the ExportToExcel extension method present in Syncfusion.UI.Xaml.TreeGrid.Converter namespace.

using Syncfusion.UI.Xaml.TreeGrid.Converter;
var options = new TreeGridExcelExportingOptions();
options.ExcelVersion = ExcelVersion.Excel2013;
var excelEngine = treeGrid.ExportToExcel(options);
var workBook = excelEngine.Excel.Workbooks[0];
workBook.SaveAs("Sample.xlsx");

NOTE

SfTreeGrid exports the data to Excel using XlsIO. You can refer to the XlsIO documentation for manipulating the exported work sheets.

Export options

The exporting operation can be customized by passing TreeGridExcelExportingOptions instance as an argument to the ExportToExcel method.

Change export mode

By default, the actual value will only be exported to Excel. To export the display text, set the TreeGridExportMode property as Text.

var options = new TreeGridExcelExportingOptions();
options.ExcelVersion = ExcelVersion.Excel2013;
options.TreeGridExportMode = TreeGridExportMode.Text;
var excelEngine = treeGrid.ExportToExcel(options);
var workBook = excelEngine.Excel.Workbooks[0];
workBook.SaveAs("Sample.xlsx");

Export without outlines

By default, all the children in the tree grid will be exported in expanded state. You can disable the outlines in Excel by setting the AllowOutliningGroups property to false in TreeGridExcelExportingOptions class.

var options = new TreeGridExcelExportingOptions();
options.ExcelVersion = ExcelVersion.Excel2013;
options.AllowOutliningGroups = false;
var excelEngine = treeGrid.ExportToExcel(options);
var workBook = excelEngine.Excel.Workbooks[0];
workBook.SaveAs("Sample.xlsx");

WPF TreeGrid Data Exporting to Excel without Outlines

Exclude columns when exporting

By default, all the columns (including hidden columns) in the tree grid will be exported to Excel. To exclude some columns, use ExcludeColumns field in TreeGridExcelExportingOptions class.

var options = new TreeGridExcelExportingOptions();
options.ExcelVersion = ExcelVersion.Excel2013;
options.ExcludeColumns.Add("FirstName");
options.ExcludeColumns.Add("LastName");
var excelEngine = treeGrid.ExportToExcel(options);
var workBook = excelEngine.Excel.Workbooks[0];
workBook.SaveAs("Sample.xlsx");

Here, the columns having FirstName and LastName as MappingName are excluded when exporting.

Excel version

When exporting to Excel, you can specify the Excel version by using the ExcelVersion property.

var options = new TreeGridExcelExportingOptions();
options.ExcelVersion = ExcelVersion.Excel2013;
var excelEngine = treeGrid.ExportToExcel(options);
var workBook = excelEngine.Excel.Workbooks[0];
workBook.SaveAs("Sample.xlsx");

Export stacked headers to Excel

You can export the stacked headers to Excel by setting the ExportStackedHeaders property to true.

var options = new TreeGridExcelExportingOptions();
options.ExcelVersion = ExcelVersion.Excel2013;
options.ExportStackedHeaders = true;
var excelEngine = treeGrid.ExportToExcel(options);
var workBook = excelEngine.Excel.Workbooks[0];
workBook.SaveAs("Sample.xlsx");

You can export the hyper-link to Excel by setting the CanExportHyperLink property to true.

var options =new TreeGridExcelExportingOptions();
options.ExcelVersion = ExcelVersion.Excel2013;
options.CanExportHyperLink = true;
var excelEngine = treeGrid.ExportToExcel(options);
var workBook = excelEngine.Excel.Workbooks[0];
workBook.SaveAs("Sample.xlsx");

The default value of the CanExportHyperLink property is true.

Export column width to Excel

You can export the columns with its actual width by setting the ExportColumnWidth property to true.

var options =new TreeGridExcelExportingOptions();
options.ExcelVersion = ExcelVersion.Excel2013;
options.ExportColumnWidth = true;
var excelEngine = treeGrid.ExportToExcel(options);
var workBook = excelEngine.Excel.Workbooks[0];
workBook.SaveAs("Sample.xlsx");

The default value of the ExportColumnWidth property is true.

Export with customized row height

You can export the tree grid to Excel with customized row height by using the DefaultRowHeight property.

var options =new TreeGridExcelExportingOptions();
options.ExcelVersion = ExcelVersion.Excel2013;
options.DefaultRowHeight = 60;
var excelEngine = treeGrid.ExportToExcel(options);
var workBook = excelEngine.Excel.Workbooks[0];
workBook.SaveAs("Sample1.xlsx");

Export without grid lines

You can export the tree grid to Excel without grid lines by setting the IsGridLinesVisible property to false.

var options =new TreeGridExcelExportingOptions();
options.ExcelVersion = ExcelVersion.Excel2013;
options.IsGridLinesVisible = true;
var excelEngine = treeGrid.ExportToExcel(options);
var workBook = excelEngine.Excel.Workbooks[0];
workBook.SaveAs("Sample.xlsx");

The default value of the IsGridLinesVisible property is true.

Export with indent column

You can export the tree grid to Excel with indent column to denote the nodes level by setting the AllowIndentColumn property to true.

var options =new TreeGridExcelExportingOptions();
options.ExcelVersion = ExcelVersion.Excel2013;
options.AllowIndentColumn = true;
var excelEngine = treeGrid.ExportToExcel(options);
var workBook = excelEngine.Excel.Workbooks[0];
workBook.SaveAs("Sample1.xlsx");

The default value of the AllowIndentColumn property is false.

Change the node expand state in Excel

You can change the node expanding state in Excel by using the NodeExpandMode property.

var options =new TreeGridExcelExportingOptions();
options.ExcelVersion = ExcelVersion.Excel2013;
options.NodeExpandMode = NodeExpandMode.CollapseAll;
var excelEngine = treeGrid.ExportToExcel(options);
var workBook = excelEngine.Excel.Workbooks[0];
workBook.SaveAs("Sample.xlsx");

Change start row and column index while exporting

You can export the data to a specified row and column index in the worksheet, by setting the ExcelStartRowIndex  and ExcelStartColumnIndex properties.

var options = new TreeGridExcelExportingOptions();
options.ExcelVersion = ExcelVersion.Excel2013;
options.ExcelStartColumnIndex = 3;
options.ExcelStartRowIndex = 3;
var excelEngine = treeGrid.ExportToExcel(options);
var workBook = excelEngine.Excel.Workbooks[0];
workBook.SaveAs("Sample.xlsx");

Changing Row and Column Index while Exporting from WPF TreeGrid to Excel

Save options

Save Excel directory to file

After exporting to Excel, you can save the exported workbook directly to the file system using the SaveAs method.

var options = new TreeGridExcelExportingOptions();
options.ExcelVersion = ExcelVersion.Excel2013;
var excelEngine = treeGrid.ExportToExcel(options);
var workBook = excelEngine.Excel.Workbooks[0];
workBook.SaveAs("Sample.xlsx");

Save Excel to stream

After exporting to Excel, you can save the exported workbook to stream using the SaveAs method.

var options = new TreeGridExcelExportingOptions();
options.ExcelVersion = ExcelVersion.Excel2013;
var excelEngine = treeGrid.ExportToExcel(options);
var workBook = excelEngine.Excel.Workbooks[0];
FileStream fileStream = new FileStream("Output.xlsx", FileMode.Create);
workBook.SaveAs(fileStream);

You can refer to the XlsIO documentation.

Save Excel using File dialog

After exporting to Excel, you can save the exported workbook by opening the FileDialog.

var options = new TreeGridExcelExportingOptions();
options.ExcelVersion = ExcelVersion.Excel2013;
var excelEngine = treeGrid.ExportToExcel(options);
var workBook = excelEngine.Excel.Workbooks[0];
SaveFileDialog sfd = new SaveFileDialog
{
    FilterIndex = 2,
    Filter = "Excel 97 to 2003 Files(*.xls)|*.xls|Excel 2007 to 2010 Files(*.xlsx)|*.xlsx|Excel 2013 File(*.xlsx)|*.xlsx"
};

if (sfd.ShowDialog() == true)
{
    using (Stream stream = sfd.OpenFile())
    {

        if (sfd.FilterIndex == 1)
            workBook.Version = ExcelVersion.Excel97to2003;

        else if (sfd.FilterIndex == 2)
            workBook.Version = ExcelVersion.Excel2010;

        else
            workBook.Version = ExcelVersion.Excel2013;
        workBook.SaveAs(stream);
    }

    //Message box confirmation to view the created workbook.

    if (MessageBox.Show("Do you want to view the workbook?", "Workbook has been created",
                        MessageBoxButton.YesNo, MessageBoxImage.Information) == MessageBoxResult.Yes)
    {

        //Launching the Excel file using the default Application.[MS Excel Or Free ExcelViewer]
        System.Diagnostics.Process.Start(sfd.FileName);
    }
}
}

Open exported Excel without saving in disk

You can open the exported workbook without saving by using the SfSpreadsheet control.

var options = new TreeGridExcelExportingOptions();
options.ExcelVersion = ExcelVersion.Excel2013;
var excelEngine = treeGrid.ExportToExcel(options);
var workBook = excelEngine.Excel.Workbooks[0];
Window1 window1 = new Window1();
SfSpreadsheet spreadsheet = new SfSpreadsheet();
spreadsheet.Open(workBook);
window1.Content = spreadsheet;
window1.Show();

WPF TreeGrid Data Exporting to Spreadsheet without Saving

Export to HTML

You can save the exported workbook as HTML by using the SaveAsHtml method.

var options = new TreeGridExcelExportingOptions();
options.ExcelVersion = ExcelVersion.Excel2013;
options.AllowOutliningGroups = false;
var excelEngine = treeGrid.ExportToExcel(options);
var workBook = excelEngine.Excel.Workbooks[0];
workBook.SaveAsHtml("Sample.html", HtmlSaveOptions.Default);

It is also possible to save the worksheet as HTML by using the SaveAsHtml method. You can refer toXlsIO documentation.

Export to mail

You can export the tree grid to mail by converting to Excel and save the exported worksheet as HTML. Then the exported HTML contents should be embedded in the mail body.

var options = new TreeGridExcelExportingOptions();
options.ExcelVersion = ExcelVersion.Excel2013;
var excelEngine = treeGrid.ExportToExcel(options);
var workBook = excelEngine.Excel.Workbooks[0];
workBook.Worksheets[0].UsedRange.BorderInside(ExcelLineStyle.Thick, ExcelKnownColors.Black);
    workBook.Worksheets[0].UsedRange.BorderAround(ExcelLineStyle.Thick, ExcelKnownColors.Black);
    workBook.Worksheets[0].SaveAsHtml("test.htm", Syncfusion.XlsIO.Implementation.HtmlSaveOptions.Default);

    System.Net.Mail.MailMessage myMessage = new System.Net.Mail.MailMessage();

    myMessage.To.Add("Support@syncfusion.com");
    myMessage.From = new MailAddress("Support@syncfusion.com");
    myMessage.Priority = MailPriority.High;
    myMessage.Subject = "Order Details";
    myMessage.IsBodyHtml = true;
    myMessage.Body = new StreamReader("test.htm").ReadToEnd();

    SmtpClient client = new SmtpClient("smtp.office365.com", 587);

    client.EnableSsl = true;
    client.UseDefaultCredentials = false;
    client.Credentials = new NetworkCredential("Support@syncfusion.com", "test");

    int count = 0;

    while (count < 3)
    {

        try
        {
            client.Send(myMessage);
            count = 3;
        }

        catch (Exception ex)
        {
            Console.WriteLine(ex.Message);
            Console.WriteLine(String.Format("Sending Mail Attemp - {0}", count.ToString()));
            Thread.Sleep(60000);
            count++;
        }
    }
    Console.WriteLine("Mail has been sent...");
}

Export to XML

You can save the exported workbook as Xml file using the SaveAsXml method.

var options = new TreeGridExcelExportingOptions();
options.ExcelVersion = ExcelVersion.Excel2013;
var excelEngine = treeGrid.ExportToExcel(options);
var workBook = excelEngine.Excel.Workbooks[0];
workBook.SaveAsXml("Sample.xml", ExcelXmlSaveType.MSExcel);

Export to CSV

You can save the exported workbook as CSV using the SaveAs method.

var options = new TreeGridExcelExportingOptions();
options.ExcelVersion = ExcelVersion.Excel2013;
var excelEngine = treeGrid.ExportToExcel(options);
var workBook = excelEngine.Excel.Workbooks[0];
workBook.SaveAs("Sample.csv", ",");

Similarly, you can also save the exported worksheet to CSV. Refer to the  XlsIO documentation.

Customize row height and column width

After exporting the data to Excel, you can set different row heights and column widths for the columns. You can refer to here for more information.

var options = new TreeGridExcelExportingOptions();
options.ExcelVersion = ExcelVersion.Excel2013;
var excelEngine = treeGrid.ExportToExcel(options);
var workBook = excelEngine.Excel.Workbooks[0];
workBook.Worksheets[0].SetRowHeight(2, 50);
workBook.Worksheets[0].SetColumnWidth(2, 50);
workBook.SaveAs("Sample.xlsx");

Customize Cell appearance when exporting

You can customize the cells by setting the ExportingEventHandler in TreeGridExcelExportingOptions.

Cell styling cells based on cell type in Excel

You can customize the cell styles based on the cell type by using the ExportingEventHandler.

var options = new TreeGridExcelExportingOptions();
options.ExcelVersion = ExcelVersion.Excel2013;
options.ExportingEventHandler = ExportingHandler;
var excelEngine = treeGrid.ExportToExcel(options);
var workBook = excelEngine.Excel.Workbooks[0];
workBook.SaveAs("Sample.xlsx");

private static void ExportingHandler(object sender, TreeGridExcelExportingEventArgs e)
{
    if (e.CellType == TreeGridCellType.HeaderCell)
    {
        e.Style.ColorIndex = ExcelKnownColors.Pink;
        e.Handled = true;
    }

    else if (e.CellType == TreeGridCellType.RecordCell)
    {
        e.Style.ColorIndex = ExcelKnownColors.Sky_blue;
        e.Handled = true;
    }
}

Customizing Cell Style in Exported WPF TreeGrid Data

Customize the exporting content to Excel

You can customize the cell values when exporting to Excel by using the CellsExportingEventHandler in  TreeGridExcelExportingOptions.

var options = new TreeGridExcelExportingOptions();
options.ExcelVersion = ExcelVersion.Excel2013;
options.CellsExportingEventHandler = CellExportingHandler;
var excelEngine = treeGrid.ExportToExcel(options);
var workBook = excelEngine.Excel.Workbooks[0];
workBook.SaveAs("Sample.xlsx");

private static void CellExportingHandler(object sender, TreeGridCellExcelExportingEventArgs e)
{
    // Based on the column mapping name and the cell type, we can change the cell 
    //values while exporting to excel.
    if (e.CellType == TreeGridCellType.RecordCell && e.ColumnName == "IsClosed")
    {
        //if the cell value is True, "Y" will be displayed else "N" will be displayed.

        if (e.CellValue.Equals(true))
            e.Range.Cells[0].Value = "Y";

        else
            e.Range.Cells[0].Value = "N";
        e.Handled = true;
    }
}

Customizing Exported WPF TreeGrid Content to Excel

Here, the cell values changed for the IsClosed column are based on the custom condition.

Change row style in Excel based on data

You can customize the rows based on the record values by using the CellsExportingEventHandler.

var options = new TreeGridExcelExportingOptions();
options.ExcelVersion = ExcelVersion.Excel2013;
options.CellsExportingEventHandler = CellExportingHandler;
var excelEngine = treeGrid.ExportToExcel(options);
var workBook = excelEngine.Excel.Workbooks[0];
workBook.SaveAs("Sample.xlsx");

private static void CellExportingHandler(object sender, TreeGridCellExcelExportingEventArgs e)
{
    if ((e.Node==null))
        return;
    var record = e.Node as EmployeeInfo;

    if (record.City == "NewYork")
    {
        e.Range.CellStyle.ColorIndex = ExcelKnownColors.Green;
        e.Range.CellStyle.Font.Color = ExcelKnownColors.White;
    }
}

Changing Row Style in Excel Sheet based on WPF TreeGrid Data

Customize the cells based on column name

You can customize the cells based on the GridCellExcelExportingEventArgs.ColumnName property in CellsExportingEventHandler.

var options = new TreeGridExcelExportingOptions();
options.ExcelVersion = ExcelVersion.Excel2013;
options.AllowOutliningGroups = false;
options.CellsExportingEventHandler = CellExportingHandler;
var excelEngine = treeGrid.ExportToExcel(options);
var workBook = excelEngine.Excel.Workbooks[0];
workBook.SaveAs("Sample.xlsx");

private static void CellExportingHandler(object sender, TreeGridCellExcelExportingEventArgs e)
{
    if (e.ColumnName != "ID")
        return;

    e.Range.CellStyle.Font.Size = 12;
    e.Range.CellStyle.Font.Color = ExcelKnownColors.Pink;
    e.Range.CellStyle.Font.FontName = "Segoe UI";
}

Customizing Cells based on Column in Exported WPF TreeGrid Data

Customize exported workbook and worksheet

The tree grid can be exported to Excel using XlsIO. You can refer to the XlsIO documentation for manipulating the workbooks and sheets after exporting.

Set borders

You can set the borders to Excel cells by directly accessing worksheet after exporting the data.

var options = new TreeGridExcelExportingOptions();
options.ExcelVersion = ExcelVersion.Excel2013;
var excelEngine = treeGrid.ExportToExcel(options);
var workBook = excelEngine.Excel.Workbooks[0];
workBook.Worksheets[0].UsedRange.BorderInside(ExcelLineStyle.Dash_dot, ExcelKnownColors.Black);
workBook.Worksheets[0].UsedRange.BorderAround(ExcelLineStyle.Dash_dot, ExcelKnownColors.Black);
workBook.SaveAs("Sample.xlsx");

Changing Cell Border Style in Exported WPF TreeGrid Data

Enable filters

You can show filters in the exported worksheet by enabling filter for the exported range.

var options = new TreeGridExcelExportingOptions();
options.ExcelVersion = ExcelVersion.Excel2013;
var excelEngine = treeGrid.ExportToExcel(options);
var workBook = excelEngine.Excel.Workbooks[0];
workBook.Worksheets[0].AutoFilters.FilterRange = workBook.Worksheets[0].UsedRange;
workBook.SaveAs("Sample.xlsx");

Displaying Filter in Exported WPF TreeGrid Data

When using the stacked headers, you can specify the range based on the stacked headers count.

var options = new TreeGridExcelExportingOptions();
options.ExcelVersion = ExcelVersion.Excel2013;
var excelEngine = treeGrid.ExportToExcel(options);
var workBook = excelEngine.Excel.Workbooks[0];
var range = "A" + (treeGrid.StackedHeaderRows.Count + 1).ToString() + ":" + workBook.Worksheets[0].UsedRange.End.AddressLocal;
excelEngine.Excel.Workbooks[0].Worksheets[0].AutoFilters.FilterRange = workBook.Worksheets[0].Range[range];
workBook.SaveAs("Sample.xlsx");

You can refer to the XlsIO documentation.

Customize the range of cells

You can customize the range of cells after exporting to Excel by directly manipulating the worksheet.

var options = new TreeGridExcelExportingOptions();
options.ExcelVersion = ExcelVersion.Excel2013;
var excelEngine = treeGrid.ExportToExcel(options);
var workBook = excelEngine.Excel.Workbooks[0];
workBook.Worksheets[0].Range["A2:A6"].CellStyle.Color = System.Drawing.Color.LightSlateGray;
workBook.Worksheets[0].Range["A2:A6"].CellStyle.Font.Color = ExcelKnownColors.White;
workBook.SaveAs("Sample.xlsx");

Customizing Range of Cells in Exported WPF TreeGrid Data

Performance

Using the ExcelExportingOptions.CellsExportingEventHandler and changing the settings for each cell will consume more memory and time. So, avoid using the CellsExportingEventHandler and instead of this, you can do the required settings in the exported sheet.

Format column without using CellsExportingEventHandler

You can perform cell level customizations such as row-level styling, formatting a particular column in the exported worksheet.
In the following code snippet, NumberFormat for Employee ID column is changed in the exported sheet after exporting without using the CellsExportingEventHandler.

Reference:
https://help.syncfusion.com/file-formats/xlsio/working-with-cell-or-range-formatting

var options = new TreeGridExcelExportingOptions();
options.TreeGridExportMode = TreeGridExportMode.Value;
options.ExcelVersion = ExcelVersion.Excel2013;
var excelEngine = treeGrid.ExportToExcel(options);
IWorkbook workBook = excelEngine.Excel.Workbooks[0];
workBook.ActiveSheet.Columns[2].NumberFormat = "0.0";
workBook.SaveAs("Sample.xlsx");

Formatting Column in Exported WPF TreeGrid Data

Alternate row styling without using CellsExportingEventHandler

In the following code snippet, the background color of the rows in Excel is changed based on the row index using conditional formatting for better performance.

Reference:
https://help.syncfusion.com/file-formats/xlsio/working-with-conditional-formatting

var options = new TreeGridExcelExportingOptions();
options.TreeGridExportMode = TreeGridExportMode.Value;
options.ExcelVersion = ExcelVersion.Excel2013;
var excelEngine = treeGrid.ExportToExcel(options);
IWorkbook workBook = excelEngine.Excel.Workbooks[0];
IConditionalFormats condition = workBook.ActiveSheet.Range[2, 1, this.treeGrid.View.Nodes.Count + 1, this.treeGrid.Columns.Count].ConditionalFormats;
IConditionalFormat condition1 = condition.AddCondition();
condition1.FormatType = ExcelCFType.Formula;
condition1.FirstFormula = "MOD(ROW(),2)=0";
condition1.BackColorRGB = System.Drawing.Color.Pink;
IConditionalFormat condition2 = condition.AddCondition();
condition2.FormatType = ExcelCFType.Formula;
condition2.FirstFormula = "MOD(ROW(),2)=1";
condition2.BackColorRGB = System.Drawing.Color.LightGray;
workBook.SaveAs("Sample.xlsx");

Changing Style of Alternate Rows in Exported WPF TreeGrid Data

How to

Export multiple tree grids to single Excel sheet

You can export multiple tree grids to single Excel sheet by merging one tree grid worksheet into another using the Worksheet.UsedRange.CopyTo method.

var options = new TreeGridExcelExportingOptions();
options.ExcelVersion = ExcelVersion.Excel2010;

var excelEngine = treeGrid.ExportToExcel(options);
var workBook1 = excelEngine.Excel.Workbooks[0];
var worksheet1 = workBook1.Worksheets[0];
            
excelEngine = treeGrid1.ExportToExcel(options);
var workBook2 = excelEngine.Excel.Workbooks[0];
var worksheet2 = workBook2.Worksheets[0];

var columnCount = this.treeGrid1.Columns.Count;
//Merge the One TreeGrid WorkSheet into the other TreeGrid WorkSheet
worksheet2.UsedRange.CopyTo(worksheet1[1, columnCount + 1]);
workBook1.SaveAs("sample.xlsx");

Export the tree grid that is not loaded in view

You can export the tree grid that is not loaded in view by calling the ApplyTemplate() method before exporting.

var options = new TreeGridExcelExportingOptions();
options.ExcelVersion = ExcelVersion.Excel2010;
treeGrid1.ApplyTemplate();
var excelEngine = treeGrid1.ExportToExcel(options);
var workBook1 = excelEngine.Excel.Workbooks[0];
var worksheet1 = workBook1.Worksheets[0];
workBook1.SaveAs("sample.xlsx");

Export parent and expanded child nodes

By default, all the tree grid nodes will be exported when calling the ExportToExcel method. You can export only the parent and expanded child nodes by overriding theExportNodesToExcel method of TreeGridToExcelConverter class,

var options = new TreeGridExcelExportingOptions();
options.ExcelVersion = ExcelVersion.Excel2013;
var excelEngine = treeGrid.ExportToExcel(options, true);
var workBook = excelEngine.Excel.Workbooks[0];
workBook.SaveAs("Sample.xlsx");

protected override void ExportNodesToExcel(SfTreeGrid treeGrid, TreeNodes nodes, IWorksheet sheet, TreeGridExcelExportingOptions excelExportingOptions)
{
    if (!_excludeNonExpandedNodes)
    {
        base.ExportNodesToExcel(treeGrid, nodes, sheet, excelExportingOptions);
    }
    else
    {
        for (int i = 0; i < nodes.Count; i++)
        {
            TreeNode node = nodes[i];
            ExportNodeToExcel(treeGrid, node, sheet, excelExportingOptions);
            if (node.IsExpanded && node.HasChildNodes)
            {
                node.PopulateChildNodes();
                ExportNodesToExcel(treeGrid, node.ChildNodes, sheet, excelExportingOptions);
            }
        }
    }
}

You can download the sample here.

NOTE

You can refer to our WPF TreeGrid feature tour page for its groundbreaking feature representations. You can also explore our WPF TreeGrid example to know how to render and configure the treegrid.