Question

im attempting to export the datagridview to excel(.xls) in a winforms application using visual studio 2010 in C#, the problem being it is taking forever to save, so far i have 4220 rows and 20 columns. Is there a faster way to do this. NOTE: I am populating the datagridview from the saved excel file. I appreciate your help….my save code is as follows:

private void btnSave_Click(object sender, EventArgs e)
    {
        Excel.Application xlApp;
        Excel.Workbook xlWorkBook;
        Excel.Worksheet xlWorkSheet;
        object misValue = System.Reflection.Missing.Value;

        xlApp = new Excel.Application();
        xlWorkBook = xlApp.Workbooks.Add(misValue);
        xlWorkSheet = (Excel.Worksheet)xlWorkBook.Worksheets.get_Item(1);

        // Get the Header from dataGridView
        for (int h = 1; h < dataGridView1.Columns.Count + 1; h++)
        {
            xlWorkSheet.Cells[1, h] = dataGridView1.Columns[h - 1].HeaderText;
        }

        // Get the Cell Values
        for (int i = 0; i < dataGridView1.Rows.Count - 1; i++)
        {
            for (int j = 0; j < dataGridView1.Columns.Count; j++)
            {
                DataGridViewCell cell = dataGridView1[j, i];
                xlWorkSheet.Cells[i + 2, j + 1] = cell.Value;
            }
        }

        //xlWorkBook.SaveCopyAs("\\FORM TEST.xlsx");
        xlWorkBook.SaveAs("\\GB STOCK.xls", Excel.XlFileFormat.xlWorkbookNormal, misValue, misValue, misValue, misValue, Excel.XlSaveAsAccessMode.xlExclusive, misValue, misValue, misValue, misValue, misValue);
        xlWorkBook.Close(true, misValue, misValue);
        xlApp.Quit();

        xlApp = null;
        xlWorkBook = null;
        GC.Collect();
        GC.WaitForPendingFinalizers();
        GC.Collect();      
    }

Answer 1

After having read through various searches and through the answers above i came across this code, it works extremely faster (almost instantaneous) as compared with my orginal where it took just under 2 minutes. I am very grateful for your answers above and i will look into these especially the copy and paste method which was an interesting read. I am a relatively new to this (new hobby) and am only beginning to understand some concepts with regards to exporting datasets etc.
I know this is by no means the best way of acheiving what i set out to but it does what i want it to at the moment. Once again thanks to all who have helped, i am learning alot.

            int cols;
            //open file 
            StreamWriter wr = new StreamWriter("GB STOCK.csv", false, Encoding.UTF8);

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

            //write rows to excel file
            for (int i = 0; i < (dgvStock.Rows.Count); 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();