Importing from XML to Excel - need to know how to append to existing Excel file

Question

Hello,
I have several XML files that I will need to import into one Excel spreadsheet. I have been able to figure out how to import an XML file to an Excel file but when I import a second XML file, the contents of the second XML overwrite the Excel spreadsheet.
I am looking for an option to append. Thanks in advance
private void XmlToExcel(string xmlFilePath, string excelFilePath)
object misValue = System.Reflection.Missing.Value;
DataSet Trans_ds = new System.Data.DataSet();
Trans_ds.ReadXml(xmlFilePath);
Excel.Application excel = new Excel.Application();
excel.Application.Workbooks.Add(true);
System.Data.DataTable table = Trans_ds.Tables[0];
Worksheet worksheet = (Worksheet)excel.ActiveSheet;
Range excelRange = (Excel.Range)worksheet.get_Range("A" + worksheet.Rows.Count, Type.Missing);
int lastRow = excelRange.get_End(XlDirection.xlUp).Row;
int ColumnIndex = 0;
int rowIndex = lastRow++;
foreach (System.Data.DataColumn col in table.Columns)
ColumnIndex++;
excel.Cells[lastRow, ColumnIndex] = col.ColumnName;
foreach (DataRow row in table.Rows)
rowIndex++;
ColumnIndex = 0;
foreach (DataColumn col in table.Columns)
ColumnIndex++;
excel.Cells[rowIndex + 1, ColumnIndex] = row[col.ColumnName];
worksheet.StandardWidth = 20.0;
worksheet.SaveAs(excelFilePath, misValue, misValue, misValue, misValue, misValue, misValue, misValue, misValue, misValue);
excel.Quit();
releaseObject(worksheet);
releaseObject(excel);

Answer 1

See if this helps.  I opened the old excel file and added the new rows into the existing workbook.
private void XmlToExcel(string xmlFilePath, string excelFilePath, Boolean append)
object misValue = System.Reflection.Missing.Value;
DataSet Trans_ds = new System.Data.DataSet();
Trans_ds.ReadXml(xmlFilePath);
Excel.Application excel = new Excel.Application();
Excel.Workbook Bk = excel.Workbooks.Add(true);
System.Data.DataTable table = Trans_ds.Tables[0];
Excel.Worksheet worksheet = (Excel.Worksheet)excel.Worksheets[1];
Excel.Range excelRange = (Excel.Range)worksheet.get_Range("A" + worksheet.Rows.Count, Type.Missing);
int lastRow = excelRange.get_End(Excel.XlDirection.xlUp).Row;
int ColumnIndex = 0;
int rowIndex = lastRow++;
foreach (System.Data.DataColumn col in table.Columns)
ColumnIndex++;
excel.Cells[lastRow, ColumnIndex] = col.ColumnName;
foreach (DataRow row in table.Rows)
rowIndex++;
ColumnIndex = 0;
foreach (DataColumn col in table.Columns)
ColumnIndex++;
excel.Cells[rowIndex + 1, ColumnIndex] = row[col.ColumnName];
worksheet.StandardWidth = 20.0;
if (append == false)
worksheet.SaveAs(excelFilePath, misValue, misValue, misValue, misValue, misValue, misValue, misValue, misValue, misValue);
else
//open old workbook
Excel.Workbook oldworkbook = (Excel.Workbook)excel.Workbooks._Open(
excelFilePath,
Type.Missing, Type.Missing, Type.Missing, Type.Missing, Type.Missing,
Type.Missing, Type.Missing, Type.Missing, Type.Missing, Type.Missing,
Type.Missing, Type.Missing);
//get first sheet in workbook
Excel.Worksheet oldxlSht = (Excel.Worksheet)oldworkbook.Worksheets[1];
//get column A of old worksheet to find last row in sheet
Excel.Range xlRange = (Excel.Range)oldxlSht.get_Range(
"A" + oldxlSht.Rows.Count, Type.Missing);
int LastRow = xlRange.get_End(Microsoft.Office.Interop.Excel.XlDirection.xlUp).Row;
int newrow = LastRow + 1;
//get last row of new worksheet
xlRange = (Excel.Range)worksheet.get_Range(
"A" + oldxlSht.Rows.Count, Type.Missing);
LastRow = xlRange.get_End(Microsoft.Office.Interop.Excel.XlDirection.xlUp).Row;
// copy rows of new worksheet to old worksheet
xlRange = (Excel.Range)worksheet.Rows["1:" + LastRow, Type.Missing];
xlRange.Copy(oldxlSht.Rows[newrow, Type.Missing]);
oldworkbook.Save();
excel.Quit();
releaseObject(oldxlSht);
releaseObject(worksheet);
releaseObject(excel);
jdweng