npoi导出excel

最近发现有很多人对excel的导入导出需求很大。根据一些网上的资料加上个人的整理把项目中的DATABLE导出到excel实现具体代码如下：
第一步首先说下功能中的优点和实现的部分：
     功能说明:
    (1) 支持web及winform从DataTable导出到Excel。
    (2) 生成速度很快。
    (3) 准确判断数据类型，不会出现身份证转数值等上面提到的一系列问题。
    (4) 如果单页条数大于65535时会新建工作表。
    (5) 列宽自适应
第二步怎么在程序中调用：
           // 列的名称
            String[] headerTitle = { "列名1", "列名", "列名3", "列名4", "列名5", "列名6", "列名7", "列名8", "列名9" };
           // 标题
            String titleName = "测试名称";
            String fileName = "文件名称";//文件名称
            DataTable _Datable = null;//数据集
            NPOIHelper.ExportExcelByWeb(_Datable, headerTitle , titleName, fileName + ".xls");
第三步：具体实现代码：
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Data;
using System.Configuration;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.HtmlControls;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.IO;
using NPOI;
using NPOI.HPSF;
using NPOI.HSSF;
using NPOI.HSSF.UserModel;
using NPOI.HSSF.Util;
using NPOI.POIFS;
using NPOI.Util;
namespace XuanRui.Common
{
     /// <summary>
     /// 功能说明:
     /// (1) 支持web及winform从DataTable导出到Excel。
     /// (2) 生成速度很快。
     /// (3) 准确判断数据类型，不会出现身份证转数值等上面提到的一系列问题。
     /// (4) 如果单页条数大于65535时会新建工作表。
     /// (5) 列宽自适应
     /// </summary>
      public class NPOIHelper
      {
          #region  DataTable导出到Excel文件
          /// <summary>
          /// DataTable导出到Excel文件
          /// </summary>
          /// <param name="dtSource">源DataTable</param>
          /// <param name="strHeaderText">表头文本</param>
          /// <param name="strFileName">保存位置</param>
          public static void Export(DataTable dtSource, String[] headersTitle, string strHeaderText, string strFileName)
          {
              using (MemoryStream ms = Export(dtSource,headersTitle, strHeaderText))
              {
                  using (FileStream fs = new FileStream(strFileName, FileMode.Create, FileAccess.Write))
                  {
                      byte[] data = ms.ToArray();
                      fs.Write(data, 0, data.Length);
                      fs.Flush();
                  }
              }
          }
          #endregion

          #region  DataTable导出到Excel的MemoryStream
          /// <summary>
           /// DataTable导出到Excel的MemoryStream
           /// </summary>
           /// <param name="dtSource">源DataTable</param>
          ///  <param name="headersTitle">列头名称</param>
           /// <param name="strHeaderText">表头文本</param>
           public static MemoryStream Export(DataTable dtSource, String[] headersTitle, string strHeaderText)
           {
               HSSFWorkbook workbook = new HSSFWorkbook();
               HSSFSheet sheet = workbook.CreateSheet();
               #region 右击文件属性相关信息
               {
                   DocumentSummaryInformation dsi = PropertySetFactory.CreateDocumentSummaryInformation();
                   dsi.Company = "公司名称“
                   workbook.DocumentSummaryInformation = dsi;
                   SummaryInformation si = PropertySetFactory.CreateSummaryInformation();
                   si.Author = "zhaolf";
                   si.ApplicationName = "创建程序信息";
                   si.LastAuthor = "zhaolf";
                   si.Comments = "软件部";
                   si.Title = "报表导出";
                   si.Subject = "报表导出";
                   si.CreateDateTime = DateTime.Now;
                   workbook.SummaryInformation = si;
               }
               #endregion

               HSSFCellStyle dateStyle = workbook.CreateCellStyle();
               HSSFDataFormat format = workbook.CreateDataFormat();
               dateStyle.DataFormat = format.GetFormat("yyyy-mm-dd");
               dateStyle.Alignment = CellHorizontalAlignment.CENTER;
               dateStyle.BorderBottom = CellBorderType.THIN;
               dateStyle.BorderTop = CellBorderType.THIN;
               dateStyle.BorderLeft = CellBorderType.THIN;
               dateStyle.BorderRight = CellBorderType.THIN;
               //取得列宽
               int[] arrColWidth = new int[dtSource.Columns.Count];
               foreach (DataColumn item in dtSource.Columns)
               {
                   arrColWidth[item.Ordinal] = Encoding.GetEncoding(936).GetBytes(item.ColumnName.ToString()).Length;
               }
               for (int index = 0; index < dtSource.Rows.Count; index++)
               {
                   for (int icount = 0; icount < dtSource.Columns.Count; icount++)
                   {
                       int intTemp = Encoding.GetEncoding(936).GetBytes(dtSource.Rows[index][icount].ToString()).Length;
                       if (intTemp > arrColWidth[icount])
                       {
                           arrColWidth[icount] = intTemp;
                       }
                   }
               }
               int rowIndex = 0;
               foreach (DataRow row in dtSource.Rows)
               {
                   #region 新建表，填充表头，填充列头，样式
                   if (rowIndex == 65535 || rowIndex == 0)
                   {
                      if (rowIndex != 0)
                      {
                          sheet = workbook.CreateSheet();
                      }
 
                      #region 表头及样式
                      {
                          HSSFRow headerRow = sheet.CreateRow(0);
                          headerRow.HeightInPoints = 25;
                          headerRow.CreateCell(0).SetCellValue(strHeaderText);
 
                          HSSFCellStyle headStyle = workbook.CreateCellStyle();
                          headStyle.Alignment = CellHorizontalAlignment.CENTER;
                         
                          HSSFFont font = workbook.CreateFont();
                          font.FontHeightInPoints = 20;
                          font.Boldweight = 700;
                          headStyle.SetFont(font);
                          headerRow.GetCell(0).CellStyle = headStyle;
                          sheet.AddMergedRegion(new Region(0, 0, 0, dtSource.Columns.Count - 1));
                          headerRow.Dispose();
                      }
                      #endregion
 
                      #region 列头及样式
                      {
                          HSSFRow headerRow = sheet.CreateRow(1);
                          HSSFCellStyle headStyle = workbook.CreateCellStyle();
                          headStyle.Alignment = CellHorizontalAlignment.CENTER;
                          // 填充列的背景色
                          headStyle.FillForegroundColor = HSSFColor.GREY_50_PERCENT.index;
                          headStyle.FillPattern = CellFillPattern.SOLID_FOREGROUND;
                          headStyle.BorderBottom = CellBorderType.THIN;
                          headStyle.BorderTop = CellBorderType.THIN;
                          headStyle.BorderLeft = CellBorderType.THIN;
                          headStyle.BorderRight= CellBorderType.THIN;
                         
                          HSSFFont font = workbook.CreateFont();
                          font.FontHeightInPoints = 10;
                          font.Boldweight = 700;
                          headStyle.SetFont(font);
                          for (int index = 0; index < headersTitle.Count(); index++)
                          {
                              headerRow.CreateCell(index).SetCellValue(headersTitle[index]);
                              headerRow.GetCell(index).CellStyle = headStyle;
                              sheet.SetColumnWidth(index, (arrColWidth[index] + 1) * 256);
                          }
                          headerRow.Dispose();
                      }
                      #endregion
                      rowIndex = 2;
                  }
                  #endregion
 
                  #region 填充内容
                  HSSFRow dataRow = sheet.CreateRow(rowIndex);
                  foreach (DataColumn column in dtSource.Columns)
                  {
                      HSSFCell newCell = dataRow.CreateCell(column.Ordinal);
                      HSSFCellStyle headStyle = workbook.CreateCellStyle();
                      headStyle.Alignment = CellHorizontalAlignment.CENTER;
                      headStyle.BorderBottom = CellBorderType.THIN;
                      headStyle.BorderTop = CellBorderType.THIN;
                      headStyle.BorderLeft = CellBorderType.THIN;
                      headStyle.BorderRight = CellBorderType.THIN;
                      //  dataRow.CreateCell(column.Ordinal).SetCellValue(column.ColumnName);
                      dataRow.GetCell(column.Ordinal).CellStyle = headStyle;
                      string drValue = row[column].ToString();
                      switch (column.DataType.ToString())
                      {
                          case "System.String":
                              newCell.SetCellValue(drValue);
                              break;
                          case "System.DateTime":
                              DateTime dateV;
                              DateTime.TryParse(drValue, out dateV);
                              newCell.SetCellValue(dateV);
                              newCell.CellStyle = dateStyle;
                              break;
                          case "System.Boolean":
                              bool boolV = false;
                              bool.TryParse(drValue, out boolV);
                              newCell.SetCellValue(boolV);
                              break;
                          case "System.Int16":
                          case "System.Int32":
                          case "System.Int64":
                          case "System.Byte":
                              int intV = 0;
                              int.TryParse(drValue, out intV);
                              newCell.SetCellValue(intV);
                              break;
                          case "System.Decimal":
                          case "System.Double":
                              double doubV = 0;
                              double.TryParse(drValue, out doubV);
                              newCell.SetCellValue(doubV);
                              break;
                          case "System.DBNull":
                              newCell.SetCellValue("");
                              break;
                          default:
                              newCell.SetCellValue("");
                              break;
                      }
                  }
                  #endregion
                  rowIndex++;
               }
               using (MemoryStream ms = new MemoryStream())
               {
                   workbook.Write(ms);
                   ms.Flush();
                   ms.Position = 0;
                   sheet.Dispose();
                   //workbook.Dispose();
                   return ms;
               }
           }

           #region 用于Web导出到EXCEL
           /// <summary>
           /// 用于Web导出
           /// </summary>
           /// <param name="dtSource">源DataTable</param>
           /// <param name="headersTitle">列标题信息集合</param>
           /// <param name="strHeaderText">表头文本</param>
           /// <param name="strFileName">文件名</param>
           public static void ExportExcelByWeb(DataTable dtSource, String[] headersTitle, string strHeaderText, string strFileName)
           {
               HttpContext curContext = HttpContext.Current;

               // 设置编码和附件格式
               curContext.Response.ContentType = "application/vnd.ms-excel";
               curContext.Response.ContentEncoding = Encoding.UTF8;
               curContext.Response.Charset = "";
               curContext.Response.AppendHeader("Content-Disposition",
                 "attachment;filename=" + HttpUtility.UrlEncode(strFileName, Encoding.UTF8));
               curContext.Response.BinaryWrite(Export(dtSource, headersTitle, strHeaderText).GetBuffer());
               curContext.Response.End();
           }
           #endregion


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

               HSSFWorkbook hssfworkbook;
               using (FileStream file = new FileStream(strFileName, 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);
               }
               return dt;
           }
           #endregion
      }
}
以上经过本人测试无误希望对有所要求的人给与帮助，谢谢光临及转载。