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
/* 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 list = new List (){ 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++; DataRow dr = dt.Rows[i]; IRow row = sheet.CreateRow(rowIndex); for (int j = 0; j < columnsCount; j++) { row.CreateCell(j).SetCellValue(dr[j].ToString()); } lblMsg.SafeCall(() => { if(i == (dt.Rows.Count - 1)) txtSql.AppendText(" 行数：" + (i+1).ToString() + "\r\n"); lblMsg.Text = string.Format("正在导出第{0}个条件，第{1}行", sqlIndex.ToString(), (i + 1).ToString()); double x = rowIndex * 1.0 / recordCount * 100; lblProgress.Text = string.Format("总行数：{0}, 当前完成总{1}行，百分占比：{2} %", recordCount.ToString(), rowIndex.ToString(), x.ToString("#0.0")); }); } FileStream outFs = new FileStream(fileName, FileMode.Open); workbook.Write(outFs); outFs.Close(); } }).ContinueWith(TaskEnded); } catch (Exception ex) { MessageBox.Show("发生异常，错误提示：" + ex.Message); } } private void TaskEnded(Task task) { txtSql.SafeCall(() => { lblMsg.Text = "全部导出完成！"; txtSql.AppendText("处理完成！\r\n"); }); } Extensions.cs
public static class Extensions { public static void SafeCall(this Control ctrl, Action callback) { if (ctrl.InvokeRequired) ctrl.Invoke(callback); else callback(); } public static void BindComboBox(this ComboBox cb, List list) { cb.DisplayMember = "Value"; cb.ValueMember = "Key"; cb.DataSource = list; } } Sql.cs
using System; using System.Collections.Generic; using System.Linq; using System.Text; namespace DataExport { public enum BusinessType { XA = 1, XB = 2 } public class Sql { /// /// 分批获取sql的where条件 /// public static string[] SqlWhereArray = { " 条件1 ", " 条件2 ", " 条件3 " }; /// /// sql的where条件说明 /// public static string[] DateRemarkArray = { "20130101至20130331", "20130401至20130630", "20130701后", }; /// /// 获取sql语句 /// /// /// /// /// /// 获取总记录数 /// /// /// /// /// 获取数据 /// /// /// ///