NPOI大数据分批写入同个Excel

实现过程：
要导出来的数据库数据量很大，一次取出来压力有点大，故分批取出来，导入到同一个Excel。
因为Excel2003版最大行数是65536行，Excel2007开始的版本最大行数是1048576行，故NPOI导出时候选择了Excel2007。

Form1.cs

[csharp] view plaincopyprint?
/*
引用命名空间：
using System.IO;
using System.Threading.Tasks;
using NPOI.HSSF.UserModel;
using NPOI.SS.UserModel;
using NPOI.XSSF.UserModel;
*/

public Form1()
{
    InitializeComponent();
    List<DictionaryEntry> list = new List<DictionaryEntry>(){
          new DictionaryEntry(1, "XA"),
          new DictionaryEntry(2, "XB")
    };
    cbType.BindComboBox(list);
}

private void CreateExcel(string fileName)
{
    if (File.Exists(fileName))
        File.Delete(fileName);

    IWorkbook workbook = new XSSFWorkbook();
    ISheet sheet = workbook.CreateSheet("Sheet1");
    FileStream sw = File.Create(fileName);
    workbook.Write(sw);
    sw.Close();
}

private void btnExport_Click(object sender, EventArgs e)
{
    try
    {
        Task.Factory.StartNew(() =>
        {
            txtSql.SafeCall(() =>
            {
                txtSql.AppendText("开始处理...\r\n");
            });

            BusinessType businessType = GetBusinessType();
            string[] sqlWhereArray = Sql.SqlWhereArray;
            string[] DateRemarkArray = Sql.DateRemarkArray;
            string fileName = string.Format("{0}.xlsx", businessType.ToString());

            CreateExcel(fileName);

            string sqlCount = Sql.GetRecordSql(businessType, "");
            int recordCount = db.ExecuteScalar(sqlCount);
            int sqlIndex = 0;
            int rowIndex = 0;
            foreach (string sqlWhre in sqlWhereArray)
            {
                sqlIndex++;
                FileStream fs = File.Open(fileName, FileMode.Open);
                IWorkbook workbook = new XSSFWorkbook(fs);
                ISheet sheet = workbook.GetSheetAt(0);
                txtSql.SafeCall(() =>
                {
                    txtSql.AppendText("条件" + sqlIndex.ToString() + "：" + DateRemarkArray[sqlIndex - 1]);
                });
                string sql = Sql.GetDataSql(businessType, sqlWhre);
                DataTable dt = db.GetDataSet(sql).Tables[0];

                int columnsCount = dt.Columns.Count;
                if (sqlIndex == 1)
                {
                    IRow row0 = sheet.CreateRow(0);
                    for (int m = 0; m < columnsCount; m++)
                    {
                        DataColumn dc = dt.Columns[m];
                        row0.CreateCell(m).SetCellValue(dc.ColumnName);
                    }
                }

                for (int i = 0; i < dt.Rows.Count; i++)
                {
                    rowIndex++;
  &nb

补充：软件开发 , C++ ,