Question

I am trying to copy DataGridView data to Excel and I am using this code:

public static void ExportToExcel(DataGridView dgView)
{
    Microsoft.Office.Interop.Excel.Application excelApp = null;

    try
    {
        // instantiating the excel application class
        object misValue = System.Reflection.Missing.Value;
        excelApp = new Microsoft.Office.Interop.Excel.Application();
        Microsoft.Office.Interop.Excel.Workbook currentWorkbook = excelApp.Workbooks.Add(Type.Missing);
        Microsoft.Office.Interop.Excel.Worksheet currentWorksheet = (Microsoft.Office.Interop.Excel.Worksheet)currentWorkbook.ActiveSheet;

        currentWorksheet.Columns.ColumnWidth = 18;

        if (dgView.Rows.Count > 0)
        {
            currentWorksheet.Cells[1, 1] = DateTime.Now.ToString("s");
            int i = 1;

            foreach (DataGridViewColumn dgviewColumn in dgView.Columns)
            {
                // Excel work sheet indexing starts with 1
                currentWorksheet.Cells[2, i] = dgviewColumn.Name;
                ++i;
            }

            Microsoft.Office.Interop.Excel.Range headerColumnRange = currentWorksheet.get_Range("A2", "G2");
            headerColumnRange.Font.Bold = true;
            headerColumnRange.Font.Color = 0xFF0000;

            //headerColumnRange.EntireColumn.AutoFit();
            int rowIndex = 0;

            for (rowIndex = 0; rowIndex < dgView.Rows.Count; rowIndex++)
            {
                DataGridViewRow dgRow = dgView.Rows[rowIndex];

                for (int cellIndex = 0; cellIndex < dgRow.Cells.Count; cellIndex++)
                {
                    currentWorksheet.Cells[rowIndex + 3, cellIndex + 1] = dgRow.Cells[cellIndex].Value;
                }
            }

            Microsoft.Office.Interop.Excel.Range fullTextRange = currentWorksheet.get_Range("A1", "G" + (rowIndex + 1).ToString());
            fullTextRange.WrapText = true;
            fullTextRange.HorizontalAlignment = Microsoft.Office.Interop.Excel.XlHAlign.xlHAlignLeft;
        }
        else
        {
            string timeStamp = DateTime.Now.ToString("s");
            timeStamp = timeStamp.Replace(':', '-');
            timeStamp = timeStamp.Replace("T", "__");
            currentWorksheet.Cells[1, 1] = timeStamp;
            currentWorksheet.Cells[1, 2] = "No error occured";
        }

        using (SaveFileDialog exportSaveFileDialog = new SaveFileDialog())
        {
            exportSaveFileDialog.Title = "Select Excel File";
            exportSaveFileDialog.Filter = "Microsoft Office Excel Workbook(*.xlsx)|*.xlsx";

            if (DialogResult.OK == exportSaveFileDialog.ShowDialog())
            {
                string fullFileName = exportSaveFileDialog.FileName;
                // currentWorkbook.SaveCopyAs(fullFileName);
                // indicating that we already saved the workbook, otherwise call to Quit() will pop up
                // the save file dialogue box

                currentWorkbook.SaveAs(fullFileName, Microsoft.Office.Interop.Excel.XlFileFormat.xlOpenXMLWorkbook, System.Reflection.Missing.Value, misValue, false, false, Microsoft.Office.Interop.Excel.XlSaveAsAccessMode.xlNoChange, Microsoft.Office.Interop.Excel.XlSaveConflictResolution.xlUserResolution, true, misValue, misValue, misValue);
                currentWorkbook.Saved = true;
                MessageBox.Show("Exported successfully", "Exported to Excel", MessageBoxButtons.OK, MessageBoxIcon.Information);
            }
        }
    }
    catch (Exception ex)
    {
        MessageBox.Show(ex.Message, "Exception", MessageBoxButtons.OK, MessageBoxIcon.Error);
    }
    finally
    {
        if (excelApp != null)
        {
            excelApp.Quit();
        }
    }
}

But as there is over 200 000 records, its taking a long time to export. Is there a faster way to do this?

Answer 1

Try this code. It’s faster than the normal interop methods, also it converts into CSV which can be read easily by excel.

int cols;
//open file 
StreamWriter wr = new StreamWriter("GB STOCK.csv");

//determine the number of columns and write columns to file 
cols = dgvStock.Columns.Count;
for (int i = 0; i < cols - 1; i++)
{ 
    wr.Write(dgvStock.Columns[i].Name.ToString().ToUpper() + ",");
} 
wr.WriteLine();

//write rows to excel file
for (int i = 0; i < (dgvStock.Rows.Count - 1); i++)
{ 
    for (int j = 0; j < cols; j++)
    { 
        if (dgvStock.Rows[i].Cells[j].Value != null)
        {
            wr.Write(dgvStock.Rows[i].Cells[j].Value + ",");
        }
        else 
        {
            wr.Write(",");
        }
    }

    wr.WriteLine();
}

//close file
wr.Close();