ASP.NET使用NPOI类库导出Excel

/*
 * 作者: 牛腩
 * 创建时间: 2010-1-4 15:15:05
 * Email: 164423073@qq.com
 * 说明: 导出EXCEL的类，使用说明见： http://msdn.microsoft.com/zh-tw/ee818993.aspx
  */

using  System;
using  System.Collections.Generic;
using  System.Data;
using  System.IO;
using  System.Linq;
using  System.Web;
using  NPOI;
using  NPOI.HPSF;
using  NPOI.HSSF;
using  NPOI.HSSF.UserModel;
using  NPOI.POIFS;
using  NPOI.Util;

public   class  DataTableRenderToExcel
{
     public   static  Stream RenderDataTableToExcel(DataTable SourceTable)
    {
        HSSFWorkbook workbook  =   new  HSSFWorkbook();
        MemoryStream ms  =   new  MemoryStream();
        HSSFSheet sheet  =  workbook.CreateSheet();
        HSSFRow headerRow  =  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  =  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;
    }

     public   static   void  RenderDataTableToExcel(DataTable SourceTable,  string  FileName)
    {
        MemoryStream ms  =  RenderDataTableToExcel(SourceTable)  as  MemoryStream;
        FileStream fs  =   new  FileStream(FileName, FileMode.Create, FileAccess.Write);
         byte [] data  =  ms.ToArray();

        fs.Write(data,  0 , data.Length);
        fs.Flush();
        fs.Close();

        data  =   null ;
        ms  =   null ;
        fs  =   null ;
    }

     public   static  DataTable RenderDataTableFromExcel(Stream ExcelFileStream,  string  SheetName,  int  HeaderRowIndex)
    {
        HSSFWorkbook workbook  =   new  HSSFWorkbook(ExcelFileStream);
        HSSFSheet sheet  =  workbook.GetSheet(SheetName);

        DataTable table  =   new  DataTable();

        HSSFRow headerRow  =  sheet.GetRow(HeaderRowIndex);
         int  cellCount  =  headerRow.LastCellNum;

         for  ( int  i  =  headerRow.FirstCellNum; i  <  cellCount; i ++ )
        {
            DataColumn column  =   new  DataColumn(headerRow.GetCell(i).StringCellValue);
            table.Columns.Add(column);
        }

         int  rowCount  =  sheet.LastRowNum;

         for  ( int  i  =  (sheet.FirstRowNum  +   1 ); i  <  sheet.LastRowNum; i ++ )
        {
            HSSFRow row  =  sheet.GetRow(i);
            DataRow dataRow  =  table.NewRow();

             for  ( int  j  =  row.FirstCellNum; j  <  cellCount; j ++ )
                dataRow[j]  =  row.GetCell(j).ToString();
        }

        ExcelFileStream.Close();
        workbook  =   null ;
        sheet  =   null ;
         return  table;
    }

     public   static  DataTable RenderDataTableFromExcel(Stream ExcelFileStream,  int  SheetIndex,  int  HeaderRowIndex)
    {
        HSSFWorkbook workbook  =   new  HSSFWorkbook(ExcelFileStream);
        HSSFSheet sheet  =  workbook.GetSheetAt(SheetIndex);

        DataTable table  =   new  DataTable();

        HSSFRow headerRow  =  sheet.GetRow(HeaderRowIndex);
         int  cellCount  =  headerRow.LastCellNum;

         for  ( int  i  =  headerRow.FirstCellNum; i  <  cellCount; i ++ )
        {
            DataColumn column  =   new  DataColumn(headerRow.GetCell(i).StringCellValue);
            table.Columns.Add(column);
        }

         int  rowCount  =  sheet.LastRowNum;

         for  ( int  i  =  (sheet.FirstRowNum  +   1 ); i  <  sheet.LastRowNum; i ++ )
        {
            HSSFRow row  =  sheet.GetRow(i);
            DataRow dataRow  =  table.NewRow();

             for  ( int  j  =  row.FirstCellNum; j  <  cellCount; j ++ )
            {
                 if  (row.GetCell(j)  !=   null )
                    dataRow[j]  =  row.GetCell(j).ToString();
            }

            table.Rows.Add(dataRow);
        }

        ExcelFileStream.Close();
        workbook  =   null ;
        sheet  =   null ;
         return  table;
    }

     ///   <summary> 读取excel
     ///  默认第一行为标头
     ///   </summary>
     ///   <param name="path"> excel文档路径 </param>
     ///   <returns></returns>
     public   static  DataTable RenderDataTableFromExcel( string  path) {
        DataTable dt  =   new  DataTable();

        HSSFWorkbook hssfworkbook;
         using  (FileStream file  =   new  FileStream(path, FileMode.Open, FileAccess.Read))
        {
            hssfworkbook  =   new  HSSFWorkbook(file);
        }
        HSSFSheet sheet  =  hssfworkbook.GetSheetAt( 0 );
        System.Collections.IEnumerator rows  =  sheet.GetRowEnumerator();

        HSSFRow headerRow  =  sheet.GetRow( 0 );
         int  cellCount  =  headerRow.LastCellNum;

         for  ( int  j  =   0 ; j  <  cellCount; j ++ )
        {
            HSSFCell cell  =  headerRow.GetCell(j);
            dt.Columns.Add(cell.ToString());
        }

         for  ( int  i  =  (sheet.FirstRowNum  +   1 ); i  <=  sheet.LastRowNum; i ++ )
        {
            HSSFRow row  =  sheet.GetRow(i);
            DataRow dataRow  =  dt.NewRow();

             for  ( int  j  =  row.FirstCellNum; j  <  cellCount; j ++ )
            {
                 if  (row.GetCell(j)  !=   null )
                    dataRow[j]  =  row.GetCell(j).ToString();
            }

            dt.Rows.Add(dataRow);
        }

         // while (rows.MoveNext())
         // {
         //     HSSFRow row = (HSSFRow)rows.Current;
         //     DataRow dr = dt.NewRow();

         //     for (int i = 0; i < row.LastCellNum; i++)
         //     {
         //         HSSFCell cell = row.GetCell(i);


         //         if (cell == null)
         //         {
         //             dr[i] = null;
         //         }
         //         else
         //         {
         //             dr[i] = cell.ToString();
         //         }
         //     }
         //     dt.Rows.Add(dr);
         // }

         return  dt;
    }
}