.NET使用NPOI組件將數據導出Excel

1、NPOI官方網站：http://npoi.codeplex.com/

可以到此網站上去下載最新的NPOI組件版本

2、.NET調用NPOI組件導入導出Excel的操作類

　　此NPOI操作類的優點如下：
   （1）支持web及winform從DataTable導出到Excel；
   （2）生成速度很快；
   （3）準確判斷數據類型，不會出現身份證轉數值等問題；
   （4）如果單頁條數大於65535時會新建工作表；
   （5）列寬自適應；

NPOI操作類 

Code highlighting produced by Actipro CodeHighlighter (freeware)http://www.CodeHighlighter.com/-->  1 using System;
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 System.Text;
using NPOI;
using NPOI.HPSF;
using NPOI.HSSF;
using NPOI.HSSF.UserModel;
using NPOI.HSSF.Util;
using NPOI.POIFS;
using NPOI.Util;  
namespace PMS.Common
{
    public class NPOIHelper
    {
        /// <summary>
        /// DataTable導出到Excel文件
        /// </summary>
        /// <param name="dtSource">源DataTable</param>
        /// <param name="strHeaderText">表頭文本</param>
        /// <param name="strFileName">保存位置</param>
        public static void Export(DataTable dtSource, string strHeaderText, string strFileName)
        {
            using (MemoryStream ms = Export(dtSource, strHeaderText))
            {
                using (FileStream fs = new FileStream(strFileName, FileMode.Create, FileAccess.Write))
                {
                    byte[] data = ms.ToArray();
                    fs.Write(data, 0, data.Length);
                    fs.Flush();
                }
            }
        }

        /// <summary>
        /// DataTable導出到Excel的MemoryStream
        /// </summary>
        /// <param name="dtSource">源DataTable</param>
        /// <param name="strHeaderText">表頭文本</param>
        public static MemoryStream Export(DataTable dtSource, string strHeaderText)
        {
            HSSFWorkbook workbook = new HSSFWorkbook();
            HSSFSheet sheet = workbook.CreateSheet();

            #region 右擊文件 屬性信息
            {
                DocumentSummaryInformation dsi = PropertySetFactory.CreateDocumentSummaryInformation();
                dsi.Company = "NPOI";
                workbook.DocumentSummaryInformation = dsi;

                SummaryInformation si = PropertySetFactory.CreateSummaryInformation();
                si.Author = "文件作者信息"; //填加xls文件作者信息
                si.ApplicationName = "創建程序信息"; //填加xls文件創建程序信息
                si.LastAuthor = "最後保存者信息"; //填加xls文件最後保存者信息
                si.Comments = "作者信息"; //填加xls文件作者信息
                si.Title = "標題信息"; //填加xls文件標題信息
                si.Subject = "主題信息";//填加文件主題信息
                si.CreateDateTime = DateTime.Now;
                workbook.SummaryInformation = si;
            }
            #endregion

            HSSFCellStyle dateStyle = workbook.CreateCellStyle();
            HSSFDataFormat format = workbook.CreateDataFormat();
            dateStyle.DataFormat = format.GetFormat("yyyy-mm-dd");

            //取得列寬
            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 i = 0; i < dtSource.Rows.Count; i++)
            {
                for (int j = 0; j < dtSource.Columns.Count; j++)
                {
                    int intTemp = Encoding.GetEncoding(936).GetBytes(dtSource.Rows[i][j].ToString()).Length;
                    if (intTemp > arrColWidth[j])
                    {
                        arrColWidth[j] = intTemp;
                    }
                }
            } 
            int rowIndex = 0; 
            foreach (DataRow row in dtSource.Rows)
            {
                #region 新建表，填充表頭，填充列頭，樣式
                if (rowIndex == 65535 || rowIndex == 0)
                {
                    if (rowIndex != 0)
                    {
                        sheet = workbook.CreateSheet();
                    }

                    #region 表頭及樣式
                    {
                        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 列頭及樣式
                    {
                        HSSFRow headerRow = sheet.CreateRow(1); 
                        HSSFCellStyle headStyle = workbook.CreateCellStyle();
                        headStyle.Alignment = CellHorizontalAlignment.CENTER;
                        HSSFFont font = workbook.CreateFont();
                        font.FontHeightInPoints = 10;
                        font.Boldweight = 700;
                        headStyle.SetFont(font); 
                        foreach (DataColumn column in dtSource.Columns)
                        {
                            headerRow.CreateCell(column.Ordinal).SetCellValue(column.ColumnName);
                            headerRow.GetCell(column.Ordinal).CellStyle = headStyle;

                            //設置列寬
                            sheet.SetColumnWidth(column.Ordinal, (arrColWidth[column.Ordinal] + 1) * 256); 
                        }
                        headerRow.Dispose();
                    }
                    #endregion

                    rowIndex = 2;
                }
                #endregion


                #region 填充內容
                HSSFRow dataRow = sheet.CreateRow(rowIndex);
                foreach (DataColumn column in dtSource.Columns)
                {
                    HSSFCell newCell = dataRow.CreateCell(column.Ordinal);

                    string drValue = row[column].ToString();

                    switch (column.DataType.ToString())
                    {
                        case "System.String"://字符串類型
                            newCell.SetCellValue(drValue);
                            break;
                        case "System.DateTime"://日期類型
                            DateTime dateV;
                            DateTime.TryParse(drValue, out dateV);
                            newCell.SetCellValue(dateV);

                            newCell.CellStyle = dateStyle;//格式化顯示
                            break;
                        case "System.Boolean"://布爾型
                            bool boolV = false;
                            bool.TryParse(drValue, out boolV);
                            newCell.SetCellValue(boolV);
                            break;
                        case "System.Int16"://整型
                        case "System.Int32":
                        case "System.Int64":
                        case "System.Byte":
                            int intV = 0;
                            int.TryParse(drValue, out intV);
                            newCell.SetCellValue(intV);
                            break;
                        case "System.Decimal"://浮點型
                        case "System.Double":
                            double doubV = 0;
                            double.TryParse(drValue, out doubV);
                            newCell.SetCellValue(doubV);
                            break;
                        case "System.DBNull"://空值處理
                            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();//一般只用寫這一個就OK了，他會遍歷並釋放所有資源，但當前版本有問題所以只釋放sheet
                return ms;
            } 
        }

        /// <summary>
        /// 用於Web導出
        /// </summary>
        /// <param name="dtSource">源DataTable</param>
        /// <param name="strHeaderText">表頭文本</param>
        /// <param name="strFileName">文件名</param>
        public static void ExportByWeb(DataTable dtSource, string strHeaderText, string strFileName)
        { 
            HttpContext curContext = HttpContext.Current;

            // 設置編碼和附件格式
            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, strHeaderText).GetBuffer());
            curContext.Response.End(); 
        } 

        /// <summary>讀取excel
        /// 默認第一行爲標頭
        /// </summary>
        /// <param name="strFileName">excel文檔路徑</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;
        }
    }
}

4、NPOI操作類的調用方法
   DataTable dt_Grade = Tools.Data.GetDataTable(strSQL);
   filename += "績效考覈結果分數統計表";
   PMS.Common.NPOIHelper.ExportByWeb(dt_Grade, filename, filename+".xls");

5、效果展示

6、NPOI類庫下載：http://download.csdn.net/detail/abc456456456456/7436415