Adding data to existing excel using open xml sdk 2.5 - excel

Question

I tried to read the existing excel file and copied to another path, and then i tried to insert data to the file i cloned. But I can' insert data. I don't know where I made mistake. But Here I've given my code.
Error occured in the line sheetData.InsertAt<Row>(row,++rowIndex);. Please help me out.
Package spreadsheetPackage = Package.Open(destinationFile, FileMode.Open, FileAccess.ReadWrite);
using (var document = SpreadsheetDocument.Open(spreadsheetPackage))
{
foreach (System.Data.DataTable table in ds.Tables)
{
var workbookPart = document.WorkbookPart;
var workbook = workbookPart.Workbook;
var sheet = workbookPart.Workbook.Descendants<Sheet>().FirstOrDefault();
Worksheet ws = ((WorksheetPart)(workbookPart.GetPartById(sheet.Id))).Worksheet;
SheetData sheetData = ws.GetFirstChild<SheetData>();
//Sheet sheet = sheets.FirstOrDefault();
if(sheet==null)
throw new Exception("No sheed found in the template file. Please add the sheet");
int rowIndex = 10, colIndex = 0;
bool flag = false;
var worksheetPart = (WorksheetPart)workbookPart.GetPartById(sheet.Id);
var sharedStringPart = workbookPart.SharedStringTablePart;
var values = sharedStringPart.SharedStringTable.Elements<SharedStringItem>().ToArray();
var rows = worksheetPart.Worksheet.Descendants<Row>();
List<String> columns = new List<string>();
foreach (System.Data.DataColumn column in table.Columns)
{
columns.Add(column.ColumnName);
}
foreach (System.Data.DataRow dsrow in table.Rows)
{
Row row = new Row();
foreach (String col in columns)
{
DocumentFormat.OpenXml.Spreadsheet.Cell cell = new Cell();
cell.DataType = DocumentFormat.OpenXml.Spreadsheet.CellValues.String;
cell.CellValue = new DocumentFormat.OpenXml.Spreadsheet.CellValue(dsrow[col].ToString());
row.AppendChild<Cell>(cell);
}
sheetData.InsertAt<Row>(row,++rowIndex);
}
}

Answer 1

Before you append Row, you should mentioned the row index to the instance...
row.RowIndex = (UInt32)rowIndex++;