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();

    }

}