C#读取Excel 几种方法的体会

(1) OleDb： 用这种方法读取Excel速度还是非常的快的，但这种方式读取数据的时候不太灵活，不过可以在 DataTable 中对数据进行一些删减修改

这种方式将Excel作为一个数据源，直接用Sql语句获取数据了。所以读取之前要知道此次要读取的Sheet（当然也可以用序号，类似dt.Row[0][0]。这样倒是不需要知道Sheet）

if (fileType == ".xls")
   connStr = "Provider=Microsoft.Jet.OLEDB.4.0;" + "Data Source=" + fileName + ";" + ";Extended Properties=\"Excel 8.0;HDR=YES;IMEX=1\"";
else
   connStr = "Provider=Microsoft.ACE.OLEDB.12.0;" + "Data Source=" + fileName + ";" + ";Extended Properties=\"Excel 12.0;HDR=YES;IMEX=1\"";

OleDbConnection conn new OleDbConnection(connStr);
DataTable dtSheetName = conn.GetOleDbSchemaTable(OleDbSchemaGuid.Tables, new object[] { null, null, null, "TABLE" });

以上是读取Excel的Sheet名，xls和xlsx的连接字符串也不一样的，可以根据文件的后缀来区别。这里需要注意的一点，Excel里面只有一个Sheet，但通过这种方式读取Sheet可能会大于一个。原因已经有人在别的网站说过了，偷一下懒O(∩_∩)O，下面文段来自【cdwolfling】

【在使用过程中发现取出的Sheet和实际excel不一致， 会多出不少。目前总结后有两种情况：

1. 取出的名称中，包括了XL命名管理器中的名称（参见XL2007的公式--命名管理器， 快捷键Crtl+F3）；

2. 取出的名称中，包括了FilterDatabase后缀的， 这是XL用来记录Filter范围的， 参见http://www.mrexcel.com/forum/showthread.php?t=27225；

对于第一点比较简单， 删除已有命名管理器中的内容即可；第二点处理起来比较麻烦， Filter删除后这些名称依然保留着，简单的做法是新增sheet然后将原sheet Copy进去】

---------------------------------

但实际情况并不能为每个Excel做以上检查，【cdwolfling】也给出了过滤的方案，当时还是有点问题，本来补充了一点。总之先看代码吧

for (int i = 0; i < dtSheetName.Rows.Count; i++)

{

SheetName = (string)dtSheetName.Rows[i]["TABLE_NAME"];

if (SheetName .Contains("$") && !SheetName .Replace("'", "").EndsWith("$"))continue;//过滤无效SheetName完毕....

da.SelectCommand = new OleDbCommand(String.Format(sql_F, tblName), conn);
DataSet dsItem = new DataSet();
da.Fill(dsItem, tblName);

}

因为读取出来无效SheetName一般情况最后一个字符都不会是$。如果SheetName有一些特殊符号，读取出来的SheetName会自动加上单引号，比如在Excel中将SheetName编辑成：MySheet(1)，此时读取出来的SheetName就为：'MySheet(1)$'，所以判断最后一个字符是不是$之前最好过滤一下单引号。

优点：读取方式简单、读取速度快

缺点：除了读取过程不太灵活之外，这种读取方式还有个弊端就是，当Excel数据量很大时。会非常占用内存，当内存不够时会抛出内存溢出的异常。

不过一般情况下还是非常不错的

 读取Excel完整代码：

/// <summary>
        /// 读取Excel文件到DataSet中
        /// </summary>
        /// <param name="filePath">文件路径</param>
        /// <returns></returns>
        public static DataSet ToDataTable(string filePath)
        {
            string connStr = "";            
            string fileType = System.IO.Path.GetExtension(fileName);
            if (string.IsNullOrEmpty(fileType)) return null;

            if (fileType == ".xls")
                connStr = "Provider=Microsoft.Jet.OLEDB.4.0;" + "Data Source=" + filePath+ ";" + ";Extended Properties=\"Excel 8.0;HDR=YES;IMEX=1\"";
            else
                connStr = "Provider=Microsoft.ACE.OLEDB.12.0;" + "Data Source=" + filePath+ ";" + ";Extended Properties=\"Excel 12.0;HDR=YES;IMEX=1\"";
            string sql_F = "Select * FROM [{0}]";

            OleDbConnection conn = null;
            OleDbDataAdapter da = null;
            DataTable dtSheetName= null;

            DataSet ds = new DataSet();
            try
            {
                // 初始化连接，并打开
                conn = new OleDbConnection(connStr);
                conn.Open();

                // 获取数据源的表定义元数据                        
                string SheetName = "";
                dtSheetName= conn.GetOleDbSchemaTable(OleDbSchemaGuid.Tables, new object[] { null, null, null, "TABLE" });

                // 初始化适配器
                da = new OleDbDataAdapter();
                for (int i = 0; i < dtSheetName.Rows.Count; i++)
                {
                    SheetName = (string)dtSheetName.Rows[i]["TABLE_NAME"];

                    if (SheetName .Contains("$") && !SheetName .Replace("'", "").EndsWith("$"))
                    {
                        continue;
                    }

                    da.SelectCommand = new OleDbCommand(String.Format(sql_F, SheetName ), conn);
                    DataSet dsItem = new DataSet();
                    da.Fill(dsItem, tblName);

                    ds.Tables.Add(dsItem.Tables[0].Copy());
                }
            }
            catch (Exception ex)
            {
            }
            finally
            {
                // 关闭连接
                if (conn.State == ConnectionState.Open)
                {
                    conn.Close();
                    da.Dispose();
                    conn.Dispose();
                }
            }
            return ds;
        }

　　

(2)：Com组件的方式读取Excel

这种方式需要先引用 Microsoft.Office.Interop.Excel 。首选说下这种方式的优缺点

优点：可以非常灵活的读取Excel中的数据

缺点：如果是Web站点部署在IIS上时，还需要服务器机子已安装了Excel，有时候还需要为配置IIS权限。最重要的一点因为是基于单元格方式读取的，所以数据很慢（曾做过试验，直接读取千行、200多列的文件，直接读取耗时15分钟。即使采用多线程分段读取来提高CPU的利用率也需要8分钟。PS：CPU I3）

需要读取大文件的的童鞋们慎重。。。

附上单线程和多线程读取类：

public class ExcelOptions
    {
        private Stopwatch wath = new Stopwatch();

        /// <summary>
        /// 使用COM读取Excel
        /// </summary>
        /// <param name="excelFilePath">路径</param>
        /// <returns>DataTabel</returns>
        public System.Data.DataTable GetExcelData(string excelFilePath)
        {
            Excel.Application app = new Excel.Application();
            Excel.Sheets sheets;
            Excel.Workbook workbook = null;
            object oMissiong = System.Reflection.Missing.Value;
            System.Data.DataTable dt = new System.Data.DataTable();

            wath.Start();

            try
            {
                if (app == null)
                {
                    return null;
                }

                workbook = app.Workbooks.Open(excelFilePath, oMissiong, oMissiong, oMissiong, oMissiong, oMissiong, oMissiong, oMissiong, oMissiong, oMissiong, oMissiong, oMissiong, oMissiong, oMissiong, oMissiong);

                //将数据读入到DataTable中——Start   

                sheets = workbook.Worksheets;
                Excel.Worksheet worksheet = (Excel.Worksheet)sheets.get_Item(1);//读取第一张表
                if (worksheet == null)
                    return null;

                string cellContent;
                int iRowCount = worksheet.UsedRange.Rows.Count;
                int iColCount = worksheet.UsedRange.Columns.Count;
                Excel.Range range;

                //负责列头Start
                DataColumn dc;
                int ColumnID = 1;
                range = (Excel.Range)worksheet.Cells[1, 1];
                while (range.Text.ToString().Trim() != "")
                {
                    dc = new DataColumn();
                    dc.DataType = System.Type.GetType("System.String");
                    dc.ColumnName = range.Text.ToString().Trim();
                    dt.Columns.Add(dc);

                    range = (Excel.Range)worksheet.Cells[1, ++ColumnID];
                }
                //End

                for (int iRow = 2; iRow <= iRowCount; iRow++)
                {
                    DataRow dr = dt.NewRow();

                    for (int iCol = 1; iCol <= iColCount; iCol++)
                    {
                        range = (Excel.Range)worksheet.Cells[iRow, iCol];

                        cellContent = (range.Value2 == null) ? "" : range.Text.ToString();

                        //if (iRow == 1)
                        //{
                        //    dt.Columns.Add(cellContent);
                        //}
                        //else
                        //{
                            dr[iCol - 1] = cellContent;
                        //}
                    }

                    //if (iRow != 1)
                    dt.Rows.Add(dr);
                }

                wath.Stop();
                TimeSpan ts = wath.Elapsed;

                //将数据读入到DataTable中——End
                return dt;
            }
            catch
            {
                
                return null;
            }
            finally 
            {
                workbook.Close(false, oMissiong, oMissiong);
                System.Runtime.InteropServices.Marshal.ReleaseComObject(workbook);
                workbook = null;
                app.Workbooks.Close();
                app.Quit();
                System.Runtime.InteropServices.Marshal.ReleaseComObject(app);
                app = null;
                GC.Collect();
                GC.WaitForPendingFinalizers();
            }
        }


        /// <summary>
        /// 使用COM，多线程读取Excel（1 主线程、4 副线程）
        /// </summary>
        /// <param name="excelFilePath">路径</param>
        /// <returns>DataTabel</returns>
        public System.Data.DataTable ThreadReadExcel(string excelFilePath)
        {
            Excel.Application app = new Excel.Application();
            Excel.Sheets sheets = null;
            Excel.Workbook workbook = null;
            object oMissiong = System.Reflection.Missing.Value;
            System.Data.DataTable dt = new System.Data.DataTable();

            wath.Start();

            try
            {
                if (app == null)
                {
                    return null;
                }

                workbook = app.Workbooks.Open(excelFilePath, oMissiong, oMissiong, oMissiong, oMissiong, oMissiong, oMissiong, oMissiong, oMissiong, oMissiong, oMissiong, oMissiong, oMissiong, oMissiong, oMissiong);

                //将数据读入到DataTable中——Start   
                sheets = workbook.Worksheets;
                Excel.Worksheet worksheet = (Excel.Worksheet)sheets.get_Item(1);//读取第一张表
                if (worksheet == null)
                    return null;

                string cellContent;
                int iRowCount = worksheet.UsedRange.Rows.Count;
                int iColCount = worksheet.UsedRange.Columns.Count;
                Excel.Range range;

                //负责列头Start
                DataColumn dc;
                int ColumnID = 1;
                range = (Excel.Range)worksheet.Cells[1, 1];
                //while (range.Text.ToString().Trim() != "")
                while (iColCount >= ColumnID)
                {
                    dc = new DataColumn();
                    dc.DataType = System.Type.GetType("System.String");

                    string strNewColumnName = range.Text.ToString().Trim();
                    if (strNewColumnName.Length == 0) strNewColumnName = "_1";
                    //判断列名是否重复
                    for (int i = 1; i < ColumnID; i++)
                    {
                        if (dt.Columns[i - 1].ColumnName == strNewColumnName)
                            strNewColumnName = strNewColumnName + "_1";
                    }

                    dc.ColumnName = strNewColumnName;
                    dt.Columns.Add(dc);

                    range = (Excel.Range)worksheet.Cells[1, ++ColumnID];
                }
                //End

                //数据大于500条，使用多进程进行读取数据
                if (iRowCount - 1 > 500)
                {
                    //开始多线程读取数据
                    //新建线程
                    int b2 = (iRowCount - 1) / 10;
                    DataTable dt1 = new DataTable("dt1");
                    dt1 = dt.Clone();
                    SheetOptions sheet1thread = new SheetOptions(worksheet, iColCount, 2, b2 + 1, dt1);
                    Thread othread1 = new Thread(new ThreadStart(sheet1thread.SheetToDataTable));
                    othread1.Start();

                    //阻塞 1 毫秒，保证第一个读取 dt1
                    Thread.Sleep(1);

                    DataTable dt2 = new DataTable("dt2");
                    dt2 = dt.Clone();
                    SheetOptions sheet2thread = new SheetOptions(worksheet, iColCount, b2 + 2, b2 * 2 + 1, dt2);
                    Thread othread2 = new Thread(new ThreadStart(sheet2thread.SheetToDataTable));
                    othread2.Start();

                    DataTable dt3 = new DataTable("dt3");
                    dt3 = dt.Clone();
                    SheetOptions sheet3thread = new SheetOptions(worksheet, iColCount, b2 * 2 + 2, b2 * 3 + 1, dt3);
                    Thread othread3 = new Thread(new ThreadStart(sheet3thread.SheetToDataTable));
                    othread3.Start();

                    DataTable dt4 = new DataTable("dt4");
                    dt4 = dt.Clone();
                    SheetOptions sheet4thread = new SheetOptions(worksheet, iColCount, b2 * 3 + 2, b2 * 4 + 1, dt4);
                    Thread othread4 = new Thread(new ThreadStart(sheet4thread.SheetToDataTable));
                    othread4.Start();

                    //主线程读取剩余数据
                    for (int iRow = b2 * 4 + 2; iRow <= iRowCount; iRow++)
                    {
                        DataRow dr = dt.NewRow();
                        for (int iCol = 1; iCol <= iColCount; iCol++)
                        {
                            range = (Excel.Range)worksheet.Cells[iRow, iCol];
                            cellContent = (range.Value2 == null) ? "" : range.Text.ToString();
                            dr[iCol - 1] = cellContent;
                        }
                        dt.Rows.Add(dr);
                    }

                    othread1.Join();
                    othread2.Join();
                    othread3.Join();
                    othread4.Join();

                    //将多个线程读取出来的数据追加至 dt1 后面
                    foreach (DataRow dr in dt.Rows)
                        dt1.Rows.Add(dr.ItemArray);
                    dt.Clear();
                    dt.Dispose();

                    foreach (DataRow dr in dt2.Rows)
                        dt1.Rows.Add(dr.ItemArray);
                    dt2.Clear();
                    dt2.Dispose();

                    foreach (DataRow dr in dt3.Rows)
                        dt1.Rows.Add(dr.ItemArray);
                    dt3.Clear();
                    dt3.Dispose();

                    foreach (DataRow dr in dt4.Rows)
                        dt1.Rows.Add(dr.ItemArray);
                    dt4.Clear();
                    dt4.Dispose();

                    return dt1;
                }
                else
                {
                    for (int iRow = 2; iRow <= iRowCount; iRow++)
                    {
                        DataRow dr = dt.NewRow();
                        for (int iCol = 1; iCol <= iColCount; iCol++)
                        {
                            range = (Excel.Range)worksheet.Cells[iRow, iCol];
                            cellContent = (range.Value2 == null) ? "" : range.Text.ToString();
                            dr[iCol - 1] = cellContent;
                        }
                        dt.Rows.Add(dr);
                    }
                }

                wath.Stop();
                TimeSpan ts = wath.Elapsed;
                //将数据读入到DataTable中——End
                return dt;
            }
            catch
            {

                return null;
            }
            finally
            {
                workbook.Close(false, oMissiong, oMissiong);
                System.Runtime.InteropServices.Marshal.ReleaseComObject(workbook);
                System.Runtime.InteropServices.Marshal.ReleaseComObject(sheets);
                workbook = null;
                app.Workbooks.Close();
                app.Quit();
                System.Runtime.InteropServices.Marshal.ReleaseComObject(app);
                app = null;
                GC.Collect();
                GC.WaitForPendingFinalizers();
                
                /*
                object objmissing = System.Reflection.Missing.Value;

Excel.ApplicationClass application = new ApplicationClass();
Excel.Workbook book = application.Workbooks.Add(objmissing);
Excel.Worksheet sheet = (Excel.Worksheet)book.Worksheets.Add（objmissing,objmissing,objmissing,objmissing);

//操作过程 ^&%&×&……&%&&……

//释放
sheet.SaveAs(path,objmissing,objmissing,objmissing,objmissing,objmissing,objmissing,objmissing,objmissing);
System.Runtime.InteropServices.Marshal.ReleaseComObject((object)sheet);
System.Runtime.InteropServices.Marshal.ReleaseComObject((object)book);
application.Quit();
System.Runtime.InteropServices.Marshal.ReleaseComObject((object)application);
System.GC.Collect();
                 */
            }
        }


        /// <summary>
        /// 删除Excel行
        /// </summary>
        /// <param name="excelFilePath">Excel路径</param>
        /// <param name="rowStart">开始行</param>
        /// <param name="rowEnd">结束行</param>
        /// <param name="designationRow">指定行</param>
        /// <returns></returns>
        public string DeleteRows(string excelFilePath, int rowStart, int rowEnd, int designationRow)
        {
            string result = "";
            Excel.Application app = new Excel.Application();
            Excel.Sheets sheets;
            Excel.Workbook workbook = null;
            object oMissiong = System.Reflection.Missing.Value;
            try
            {
                if (app == null)
                {
                    return "分段读取Excel失败";
                }

                workbook = app.Workbooks.Open(excelFilePath, oMissiong, oMissiong, oMissiong, oMissiong, oMissiong, oMissiong, oMissiong, oMissiong, oMissiong, oMissiong, oMissiong, oMissiong, oMissiong, oMissiong);
                sheets = workbook.Worksheets;
                Excel.Worksheet worksheet = (Excel.Worksheet)sheets.get_Item(1);//读取第一张表
                if (worksheet == null)
                    return result;
                Excel.Range range;

                //先删除指定行，一般为列描述
                if (designationRow != -1)
                {
                    range = (Excel.Range)worksheet.Rows[designationRow, oMissiong];
                    range.Delete(Excel.XlDeleteShiftDirection.xlShiftUp);
                }
                Stopwatch sw = new Stopwatch();
                sw.Start();

                int i = rowStart;
                for (int iRow = rowStart; iRow <= rowEnd; iRow++, i++)
                {
                    range = (Excel.Range)worksheet.Rows[rowStart, oMissiong];
                    range.Delete(Excel.XlDeleteShiftDirection.xlShiftUp);
                }

                sw.Stop();
                TimeSpan ts = sw.Elapsed;
                workbook.Save();

                //将数据读入到DataTable中——End
                return result;
            }
            catch
            {

                return "分段读取Excel失败";
            }
            finally
            {
                workbook.Close(false, oMissiong, oMissiong);
                System.Runtime.InteropServices.Marshal.ReleaseComObject(workbook);
                workbook = null;
                app.Workbooks.Close();
                app.Quit();
                System.Runtime.InteropServices.Marshal.ReleaseComObject(app);
                app = null;
                GC.Collect();
                GC.WaitForPendingFinalizers();
            }
        }

        public void ToExcelSheet(DataSet ds, string fileName)
        {
            Excel.Application appExcel = new Excel.Application();
            Excel.Workbook workbookData = null;
            Excel.Worksheet worksheetData;
            Excel.Range range;
            try
            {
                workbookData = appExcel.Workbooks.Add(System.Reflection.Missing.Value);
                appExcel.DisplayAlerts = false;//不显示警告
                //xlApp.Visible = true;//excel是否可见
                //
                //for (int i = workbookData.Worksheets.Count; i > 0; i--)
                //{
                //    Microsoft.Office.Interop.Excel.Worksheet oWorksheet = (Microsoft.Office.Interop.Excel.Worksheet)workbookData.Worksheets.get_Item(i);
                //    oWorksheet.Select();
                //    oWorksheet.Delete();
                //}

                for (int k = 0; k < ds.Tables.Count; k++)
                {
                    worksheetData = (Excel.Worksheet)workbookData.Worksheets.Add(System.Reflection.Missing.Value, System.Reflection.Missing.Value, System.Reflection.Missing.Value, System.Reflection.Missing.Value);
                    // testnum--;
                    if (ds.Tables[k] != null)
                    {
                        worksheetData.Name = ds.Tables[k].TableName;
                        //写入标题
                        for (int i = 0; i < ds.Tables[k].Columns.Count; i++)
                        {
                            worksheetData.Cells[1, i + 1] = ds.Tables[k].Columns[i].ColumnName;
                            range = (Excel.Range)worksheetData.Cells[1, i + 1];
                            //range.Interior.ColorIndex = 15;
                            range.Font.Bold = true;
                            range.NumberFormatLocal = "@";//文本格式 
                            range.EntireColumn.AutoFit();//自动调整列宽 
                            // range.WrapText = true; //文本自动换行   
                            range.ColumnWidth = 15;
                        }
                        //写入数值
                        for (int r = 0; r < ds.Tables[k].Rows.Count; r++)
                        {
                            for (int i = 0; i < ds.Tables[k].Columns.Count; i++)
                            {
                                worksheetData.Cells[r + 2, i + 1] = ds.Tables[k].Rows[r][i];
                                //Range myrange = worksheetData.get_Range(worksheetData.Cells[r + 2, i + 1], worksheetData.Cells[r + 3, i + 2]);
                                //myrange.NumberFormatLocal = "@";//文本格式 
                                //// myrange.EntireColumn.AutoFit();//自动调整列宽 
                                ////   myrange.WrapText = true; //文本自动换行   
                                //myrange.ColumnWidth = 15;
                            }
                            //  rowRead++;
                            //System.Windows.Forms.Application.DoEvents();
                        }
                    }
                    worksheetData.Columns.EntireColumn.AutoFit();
                    workbookData.Saved = true;
                }
            }
            catch (Exception ex) { }
            finally
            {
                workbookData.SaveCopyAs(fileName);
                workbookData.Close(false, System.Reflection.Missing.Value, System.Reflection.Missing.Value);
                appExcel.Quit();
                GC.Collect();
            }
        }
    
    }

　　

(3)NPOI方式读取Excel，NPOI是一组开源的组件，类似Java的 POI。包括：NPOI、NPOI.HPSF、NPOI.HSSF、NPOI.HSSF.UserModel、NPOI.POIFS、NPOI.Util，下载的时候别只下一个噢

 

优点：读取Excel速度较快，读取方式操作灵活性

缺点：只支持03的Excel，xlsx的无法读取。由于这点，使用这种方式的人不多啊，没理由要求客户使用03版Excel吧，再说03版Excel对于行数还有限制，只支持65536行。

（听他们的开发人员说会在2012年底推出新版，支持xlsx的读取。但一直很忙没时间去关注这个事情，有兴趣的同学可以瞧瞧去）

NPOI读取Excel类：

using System;
using System.Data;
using System.IO;
using System.Web;
using NPOI;
using NPOI.HPSF;
using NPOI.HSSF;
using NPOI.HSSF.UserModel;
using NPOI.POIFS;
using NPOI.Util;
using System.Text;
using System.Configuration;

public class NPOIHelper
{
    private static int ExcelMaxRow = Convert.ToInt32(ConfigurationManager.AppSettings["ExcelMaxRow"]);
    /// <summary>
    /// 由DataSet导出Excel
    /// </summary>
    /// <param name="sourceTable">要导出数据的DataTable</param>    
    /// <param name="sheetName">工作表名称</param>
    /// <returns>Excel工作表</returns>    
    private static Stream ExportDataSetToExcel(DataSet sourceDs)
    {
        HSSFWorkbook workbook = new HSSFWorkbook();
        MemoryStream ms = new MemoryStream();

        for (int i = 0; i < sourceDs.Tables.Count; i++)
        {
            HSSFSheet sheet = (HSSFSheet)workbook.CreateSheet(sourceDs.Tables[i].TableName);
            HSSFRow headerRow = (HSSFRow)sheet.CreateRow(0);
            // handling header.            
            foreach (DataColumn column in sourceDs.Tables[i].Columns)
                headerRow.CreateCell(column.Ordinal).SetCellValue(column.ColumnName);
            // handling value.            
            int rowIndex = 1;
            foreach (DataRow row in sourceDs.Tables[i].Rows)
            {
                HSSFRow dataRow = (HSSFRow)sheet.CreateRow(rowIndex);
                foreach (DataColumn column in sourceDs.Tables[i].Columns)
                {
                    dataRow.CreateCell(column.Ordinal).SetCellValue(row[column].ToString());
                }
                rowIndex++;
            }
        }
        workbook.Write(ms);
        ms.Flush();
        ms.Position = 0;
        workbook = null;
        return ms;
    }
    /// <summary>
    /// 由DataSet导出Excel
    /// </summary>   
    /// <param name="sourceTable">要导出数据的DataTable</param>
    /// <param name="fileName">指定Excel工作表名称</param>
    /// <returns>Excel工作表</returns>    
    public static void ExportDataSetToExcel(DataSet sourceDs, string fileName)
    {
        //检查是否有Table数量超过65325
        for (int t = 0; t < sourceDs.Tables.Count; t++)
        {
            if (sourceDs.Tables[t].Rows.Count > ExcelMaxRow)
            {
                DataSet ds = GetdtGroup(sourceDs.Tables[t].Copy());
                sourceDs.Tables.RemoveAt(t);
                //将得到的ds插入 sourceDs中
                for (int g = 0; g < ds.Tables.Count; g++)
                {
                    DataTable dt = ds.Tables[g].Copy();
                    sourceDs.Tables.Add(dt);
                }
                t--;
            }
        }

        MemoryStream ms = ExportDataSetToExcel(sourceDs) as MemoryStream;
        HttpContext.Current.Response.AppendHeader("Content-Disposition", "attachment;filename=" + fileName);
        HttpContext.Current.Response.BinaryWrite(ms.ToArray());
        HttpContext.Current.ApplicationInstance.CompleteRequest();
        //HttpContext.Current.Response.End();
        ms.Close();
        ms = null;
    }
    /// <summary>
    /// 由DataTable导出Excel
    /// </summary>
    /// <param name="sourceTable">要导出数据的DataTable</param> 
    /// <returns>Excel工作表</returns>    
    private static Stream ExportDataTableToExcel(DataTable sourceTable)
    {
        HSSFWorkbook workbook = new HSSFWorkbook();
        MemoryStream ms = new MemoryStream();
        HSSFSheet sheet = (HSSFSheet)workbook.CreateSheet(sourceTable.TableName);
        HSSFRow headerRow = (HSSFRow)sheet.CreateRow(0);
        // handling header.      
        foreach (DataColumn column in sourceTable.Columns)
            headerRow.CreateCell(column.Ordinal).SetCellValue(column.ColumnName);
        // handling value.      
        int rowIndex = 1;
        foreach (DataRow row in sourceTable.Rows)
        {
            HSSFRow dataRow = (HSSFRow)sheet.CreateRow(rowIndex);
            foreach (DataColumn column in sourceTable.Columns)
            {
                dataRow.CreateCell(column.Ordinal).SetCellValue(row[column].ToString());
            }
            rowIndex++;
        }
        workbook.Write(ms);
        ms.Flush();
        ms.Position = 0;
        sheet = null;
        headerRow = null;
        workbook = null;
        return ms;
    }
    /// <summary>
    /// 由DataTable导出Excel
    /// </summary>
    /// <param name="sourceTable">要导出数据的DataTable</param>
    /// <param name="fileName">指定Excel工作表名称</param>
    /// <returns>Excel工作表</returns>
    public static void ExportDataTableToExcel(DataTable sourceTable, string fileName)
    {
        //如数据超过65325则分成多个Table导出
        if (sourceTable.Rows.Count > ExcelMaxRow)
        {
            DataSet ds = GetdtGroup(sourceTable);
            //导出DataSet
            ExportDataSetToExcel(ds, fileName);
        }
        else
        {
            MemoryStream ms = ExportDataTableToExcel(sourceTable) as MemoryStream;
            HttpContext.Current.Response.AppendHeader("Content-Disposition", "attachment;filename=" + fileName);
            HttpContext.Current.Response.BinaryWrite(ms.ToArray());
            HttpContext.Current.ApplicationInstance.CompleteRequest();
            //HttpContext.Current.Response.End();
            ms.Close();
            ms = null;
        }
    }

    /// <summary>
    /// 传入行数超过65325的Table，返回DataSet
    /// </summary>
    /// <param name="dt"></param>
    /// <returns></returns>
    public static DataSet GetdtGroup(DataTable dt)
    {
        string tablename = dt.TableName;

        DataSet ds = new DataSet();
        ds.Tables.Add(dt);

        double n = dt.Rows.Count / Convert.ToDouble(ExcelMaxRow);

        //创建表
        for (int i = 1; i < n; i++)
        {
            DataTable dtAdd = dt.Clone();
            dtAdd.TableName = tablename + "_" + i.ToString();
            ds.Tables.Add(dtAdd);
        }

        //分解数据
        for (int i = 1; i < ds.Tables.Count; i++)
        {
            //新表行数达到最大 或 基表数量不足
            while (ds.Tables[i].Rows.Count != ExcelMaxRow && ds.Tables[0].Rows.Count != ExcelMaxRow)
            {
                ds.Tables[i].Rows.Add(ds.Tables[0].Rows[ExcelMaxRow].ItemArray);
                ds.Tables[0].Rows.RemoveAt(ExcelMaxRow);

            }
        }

        return ds;
    }

    /// <summary>
    /// 由DataTable导出Excel
    /// </summary>
    /// <param name="sourceTable">要导出数据的DataTable</param>
    /// <param name="fileName">指定Excel工作表名称</param>
    /// <returns>Excel工作表</returns>
    public static void ExportDataTableToExcelModel(DataTable sourceTable, string modelpath, string modelName, string fileName, string sheetName)
    {
        int rowIndex = 2;//从第二行开始，因为前两行是模板里面的内容 
        int colIndex = 0;
        FileStream file = new FileStream(modelpath + modelName + ".xls", FileMode.Open, FileAccess.Read);//读入excel模板
        HSSFWorkbook hssfworkbook = new HSSFWorkbook(file);
        HSSFSheet sheet1 = (HSSFSheet)hssfworkbook.GetSheet("Sheet1");
        sheet1.GetRow(0).GetCell(0).SetCellValue("excelTitle");      //设置表头
        foreach (DataRow row in sourceTable.Rows)
        {   //双循环写入sourceTable中的数据
            rowIndex++;
            colIndex = 0;
            HSSFRow xlsrow = (HSSFRow)sheet1.CreateRow(rowIndex);
            foreach (DataColumn col in sourceTable.Columns)
            {
                xlsrow.CreateCell(colIndex).SetCellValue(row[col.ColumnName].ToString());
                colIndex++;
            }
        }
        sheet1.ForceFormulaRecalculation = true;
        FileStream fileS = new FileStream(modelpath + fileName + ".xls", FileMode.Create);//保存
        hssfworkbook.Write(fileS);
        fileS.Close();
        file.Close();
    }
}

　　

Config配置了 【ExcelMaxRow】值 65535