多線程導出大規模excel文件

文章有點水，和前幾篇沒有太大區別，但是單線程處理大文件導出會非常耗時間，用到多線程才能更加合理的利用資源。大文件也可能會超出excel工作表范圍。這里也有相應處理
參考：用DataGridView導入TXT文件，並導出為XLS文件
參考：c#多線程介紹（上）

private void button1_Click(object sender, EventArgs e)
{
    string fileName = "";
    openFileDialog1.Multiselect = true;
    if (openFileDialog1.ShowDialog() == DialogResult.OK)
    {
        string[] filePath = openFileDialog1.FileNames;
        foreach (string name in filePath)
        {
            fileName = name;
            Thread thread = new Thread(new ParameterizedThreadStart(Go));
            thread.Start(fileName );
        }
    }
}         

private void Go(object fileName1)
{
    string fileName = (string)fileName1;
    System.Data.DataTable dt = new System.Data.DataTable();
    StreamReader sr = new StreamReader(fileName, Encoding.UTF8);

    for (int i = 0; i < 9; i++)
    {
        dt.Columns.Add(i.ToString());
    }
    while (true)
    {
        string strLine = sr.ReadLine();
        if (string.IsNullOrEmpty(strLine) == true)
        {
            break;
        }
        else
        {
            DataRow dr = dt.NewRow();
            string[] strList = strLine.Split('|');
            int j = 0;
            for (int i = 0; i < strList.Length - 1; i++)
            {
                dr[j.ToString()] = strList[i];
                j++;
                if (j == 9)
                {
                    j = 0;
                    dt.Rows.Add(dr);
                }

            }
        }
    }
    sr.Close();
    OutPutAsExcelFile(dt,fileName);
}

        private void OutPutAsExcelFile(System.Data.DataTable dt,string fileName)
        {
            fileName += ".xls";
            Microsoft.Office.Interop.Excel.Application xlApp = new Microsoft.Office.Interop.Excel.Application();

            if (xlApp == null)
            {
                MessageBox.Show("無法創建Excel對象，您的電腦可能未安裝Excel");
                return;
            }

            Microsoft.Office.Interop.Excel.Workbooks workbooks = xlApp.Workbooks;
            Microsoft.Office.Interop.Excel.Workbook workbook = workbooks.Add(Microsoft.Office.Interop.Excel.XlWBATemplate.xlWBATWorksheet);

            MessageBox.Show(dt.Rows.Count.ToString());
            int n = dt.Rows.Count / (2 << 15) + 1;
            MessageBox.Show(n.ToString());
            if (n > 3)
            {
                for (int i = 0; i < n - 3; i++)
                {
                    xlApp.Sheets.Add();
                }
            }
            for (int i = 1; i <= n; i++)
            {
                ((Microsoft.Office.Interop.Excel.Worksheet)xlApp.Sheets[i]).Name =   i.ToString();//修改SHEET名 
            }
                for (int l = 0; l < n; l++)
                {
                    Microsoft.Office.Interop.Excel.Worksheet worksheet = (Microsoft.Office.Interop.Excel.Worksheet)workbook.Worksheets[l + 1];//取得sheet 
                    //Microsoft.Office.Interop.Excel.Worksheet worksheet2 = (Microsoft.Office.Interop.Excel.Worksheet)workbook.Worksheets[2];//取得sheet2
                    int CurrentRow = l * 65536;
                    for (int r = 0; r < 65536; r++)
                    {
                        if (r + CurrentRow == dt.Rows.Count)
                            break;
                        for (int i = 0; i < dt.Columns.Count; i++)
                        {
                            worksheet.Cells[r + 1, i + 1] = dt.Rows[r + CurrentRow][i];
                        }
                        System.Windows.Forms.Application.DoEvents();
                    }
                    worksheet.Columns.EntireColumn.AutoFit();//列寬自適
                }

            MessageBox.Show(fileName + "的簡明資料保存成功", "提示", MessageBoxButtons.OK);
            if (fileName != "")
            {
                try
                {
                    workbook.Saved = true;
                    workbook.SaveCopyAs(fileName);
                    //fileSaved = true;
                }
                catch (Exception ex)
                {
                    //fileSaved = false;
                    MessageBox.Show("導出文件時出錯,文件可能正被打開！\n" + ex.Message);
                }
            }
            xlApp.Quit();
            GC.Collect();//強行銷毀 

        }