导出到Excel中NPOI

源地址：http://www.cnblogs.com/dreamof/archive/2010/06/02/1750151.html\

1、NPOI官方网站：http://npoi.codeplex.com/

可以到此网站上去下载最新的NPOI组件版本

2、NPOI在线学习教程（中文版）：

http://www.cnblogs.com/tonyqus/archive/2009/04/12/1434209.html

感谢Tony Qu分享出NPOI组件的使用方法

3、.NET调用NPOI组件导入导出Excel的操作类
　　此NPOI操作类的优点如下：
   （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；

NPOI操作类
<!--
 
Code highlighting produced by Actipro CodeHighlighter (freeware)
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-->  1 using System;
  2 using System.Data;
  3 using System.Configuration;
  4 using System.Web;
  5 using System.Web.Security;
  6 using System.Web.UI;
  7 using System.Web.UI.HtmlControls;
  8 using System.Web.UI.WebControls;
  9 using System.Web.UI.WebControls.WebParts;
10 using System.IO;
11 using System.Text;
12 using NPOI;
13 using NPOI.HPSF;
14 using NPOI.HSSF;
15 using NPOI.HSSF.UserModel;
16 using NPOI.HSSF.Util;
17 using NPOI.POIFS;
18 using NPOI.Util;
20 namespace PMS.Common
21 {
22     public class NPOIHelper
23     {
24         /// <summary>
25         /// DataTable导出到Excel文件
26         /// </summary>
27         /// <param name="dtSource">源DataTable</param>
28         /// <param name="strHeaderText">表头文本</param>
29         /// <param name="strFileName">保存位置</param>
30        public static void Export(DataTable dtSource,string strHeaderText,string strFileName)
31         {
32            using (MemoryStream ms= Export(dtSource, strHeaderText))
33             {
34                using (FileStream fs= new FileStream(strFileName, FileMode.Create, FileAccess.Write))
35                 {
36                    byte[] data = ms.ToArray();
37                     fs.Write(data,0, data.Length);
38                     fs.Flush();
39                 }
40             }
41         }
42 
43         /// <summary>
44         /// DataTable导出到Excel的MemoryStream
45         /// </summary>
46         /// <param name="dtSource">源DataTable</param>
47         /// <param name="strHeaderText">表头文本</param>
48        public static MemoryStream Export(DataTable dtSource,string strHeaderText)
49         {
50             HSSFWorkbook workbook= new HSSFWorkbook();
51             HSSFSheet sheet= workbook.CreateSheet();
52 
53            #region 右击文件 属性信息
54             {
55                 DocumentSummaryInformation dsi= PropertySetFactory.CreateDocumentSummaryInformation();
56                 dsi.Company= "NPOI";
57                 workbook.DocumentSummaryInformation= dsi;
58 
59                 SummaryInformation si= PropertySetFactory.CreateSummaryInformation();
60                 si.Author= "文件作者信息";//填加xls文件作者信息
61                 si.ApplicationName= "创建程序信息";//填加xls文件创建程序信息
62                 si.LastAuthor= "最后保存者信息";//填加xls文件最后保存者信息
63                 si.Comments= "作者信息";//填加xls文件作者信息
64                 si.Title= "标题信息";//填加xls文件标题信息
65                 si.Subject= "主题信息";//填加文件主题信息
66                 si.CreateDateTime= DateTime.Now;
67                 workbook.SummaryInformation= si;
68             }
69            #endregion
70 
71             HSSFCellStyle dateStyle= workbook.CreateCellStyle();
72             HSSFDataFormat format= workbook.CreateDataFormat();
73             dateStyle.DataFormat= format.GetFormat("yyyy-mm-dd");
74 
75            //取得列宽
76            int[] arrColWidth= newint[dtSource.Columns.Count];
77            foreach (DataColumn itemin dtSource.Columns)
78             {
79                 arrColWidth[item.Ordinal]= Encoding.GetEncoding(936).GetBytes(item.ColumnName.ToString()).Length;
80             }
81            for (int i= 0; i< dtSource.Rows.Count; i++)
82             {
83                for (int j= 0; j< dtSource.Columns.Count; j++)
84                 {
85                    int intTemp = Encoding.GetEncoding(936).GetBytes(dtSource.Rows[i][j].ToString()).Length;
86                    if (intTemp > arrColWidth[j])
87                     {
88                         arrColWidth[j]= intTemp;
89                     }
90                 }
91             }
95            int rowIndex = 0;
97            foreach (DataRow rowin dtSource.Rows)
98             {
99                #region 新建表，填充表头，填充列头，样式
100                if (rowIndex == 65535|| rowIndex== 0)
101                 {
102                    if (rowIndex != 0)
103                     {
104                         sheet= workbook.CreateSheet();
105                     }
106 
107                    #region 表头及样式
108                     {
109                         HSSFRow headerRow= sheet.CreateRow(0);
110                         headerRow.HeightInPoints= 25;
111                         headerRow.CreateCell(0).SetCellValue(strHeaderText);
112 
113                         HSSFCellStyle headStyle= workbook.CreateCellStyle();
114                         headStyle.Alignment= CellHorizontalAlignment.CENTER;
115                         HSSFFont font= workbook.CreateFont();
116                         font.FontHeightInPoints= 20;
117                         font.Boldweight= 700;
118                         headStyle.SetFont(font);
119                         headerRow.GetCell(0).CellStyle= headStyle;
120                         sheet.AddMergedRegion(new Region(0,0, 0, dtSource.Columns.Count-1));
121                         headerRow.Dispose();
122                     }
123                    #endregion
124 
125 
126                    #region 列头及样式
127                     {
128                         HSSFRow headerRow= sheet.CreateRow(1);
131                         HSSFCellStyle headStyle= workbook.CreateCellStyle();
132                         headStyle.Alignment= CellHorizontalAlignment.CENTER;
133                         HSSFFont font= workbook.CreateFont();
134                         font.FontHeightInPoints= 10;
135                         font.Boldweight= 700;
136                         headStyle.SetFont(font);
139                        foreach (DataColumn columnin dtSource.Columns)
140                         {
141                             headerRow.CreateCell(column.Ordinal).SetCellValue(column.ColumnName);
142                             headerRow.GetCell(column.Ordinal).CellStyle= headStyle;
143 
144                            //设置列宽
145                             sheet.SetColumnWidth(column.Ordinal, (arrColWidth[column.Ordinal]+ 1)* 256);
147                         }
148                         headerRow.Dispose();
149                     }
150                    #endregion
151 
152                     rowIndex= 2;
153                 }
154                #endregion
155 
156 
157                #region 填充内容
158                 HSSFRow dataRow= sheet.CreateRow(rowIndex);
159                foreach (DataColumn columnin dtSource.Columns)
160                 {
161                     HSSFCell newCell= dataRow.CreateCell(column.Ordinal);
162 
163                    string drValue= row[column].ToString();
164 
165                    switch (column.DataType.ToString())
166                     {
167                        case "System.String"://字符串类型
168                             newCell.SetCellValue(drValue);
169                            break;
170                        case "System.DateTime"://日期类型
171                             DateTime dateV;
172                             DateTime.TryParse(drValue,out dateV);
173                             newCell.SetCellValue(dateV);
174 
175                             newCell.CellStyle= dateStyle;//格式化显示
176                            break;
177                        case "System.Boolean"://布尔型
178                            bool boolV = false;
179                            bool.TryParse(drValue,out boolV);
180                             newCell.SetCellValue(boolV);
181                            break;
182                        case "System.Int16"://整型
183                        case "System.Int32":
184                        case "System.Int64":
185                        case "System.Byte":
186                            int intV = 0;
187                            int.TryParse(drValue,out intV);
188                             newCell.SetCellValue(intV);
189                            break;
190                        case "System.Decimal"://浮点型
191                        case "System.Double":
192                            double doubV = 0;
193                            double.TryParse(drValue,out doubV);
194                             newCell.SetCellValue(doubV);
195                            break;
196                        case "System.DBNull"://空值处理
197                             newCell.SetCellValue("");
198                            break;
199                        default:
200                             newCell.SetCellValue("");
201                            break;
202                     }
203 
204                 }
205                #endregion
206 
207                 rowIndex++;
208             }
211            using (MemoryStream ms= new MemoryStream())
212             {
213                 workbook.Write(ms);
214                 ms.Flush();
215                 ms.Position= 0;
216 
217                 sheet.Dispose();
218                //workbook.Dispose();//一般只用写这一个就OK了，他会遍历并释放所有资源，但当前版本有问题所以只释放sheet
219                return ms;
220             }
222         }
223 
224         /// <summary>
225         /// 用于Web导出
226         /// </summary>
227         /// <param name="dtSource">源DataTable</param>
228         /// <param name="strHeaderText">表头文本</param>
229         /// <param name="strFileName">文件名</param>
230        public static void ExportByWeb(DataTable dtSource,string strHeaderText,stringstrFileName)
231         {
233             HttpContext curContext= HttpContext.Current;
234 
235            // 设置编码和附件格式
236             curContext.Response.ContentType= "application/vnd.ms-excel";
237             curContext.Response.ContentEncoding= Encoding.UTF8;
238             curContext.Response.Charset= "";
239             curContext.Response.AppendHeader("Content-Disposition",
240                "attachment;filename="+ HttpUtility.UrlEncode(strFileName, Encoding.UTF8));
241 
242             curContext.Response.BinaryWrite(Export(dtSource, strHeaderText).GetBuffer());
243             curContext.Response.End();
245         }
247 
248         /// <summary>读取excel
249         /// 默认第一行为标头
250         /// </summary>
251         /// <param name="strFileName">excel文档路径</param>
252         /// <returns></returns>
253        public static DataTable Import(string strFileName)
254         {
255             DataTable dt= new DataTable();
256 
257             HSSFWorkbook hssfworkbook;
258            using (FileStream file= new FileStream(strFileName, FileMode.Open, FileAccess.Read))
259             {
260                 hssfworkbook= new HSSFWorkbook(file);
261             }
262             HSSFSheet sheet= hssfworkbook.GetSheetAt(0);
263             System.Collections.IEnumerator rows= sheet.GetRowEnumerator();
264 
265             HSSFRow headerRow= sheet.GetRow(0);
266            int cellCount= headerRow.LastCellNum;
267 
268            for (int j= 0; j< cellCount; j++)
269             {
270                 HSSFCell cell= headerRow.GetCell(j);
271                 dt.Columns.Add(cell.ToString());
272             }
273 
274            for (int i= (sheet.FirstRowNum+ 1); i<= sheet.LastRowNum; i++)
275             {
276                 HSSFRow row= sheet.GetRow(i);
277                 DataRow dataRow= dt.NewRow();
278 
279                for (int j= row.FirstCellNum; j< cellCount; j++)
280                 {
281                    if (row.GetCell(j)!= null)
282                         dataRow[j]= row.GetCell(j).ToString();
283                 }
284 
285                 dt.Rows.Add(dataRow);
286             }
287            return dt;
288         }
289     }
290 }
291

4、NPOI操作类的调用方法
   DataTable dt_Grade = Tools.Data.GetDataTable(strSQL);
   filename += "绩效考核结果分数统计表";
   PMS.Common.NPOIHelper.ExportByWeb(dt_Grade, filename, filename+".xls");

5、效果展示

6、NPOI类库下载：http://files.cnblogs.com/dreamof/NPOI类库.rar

信息来源：http://www.cnblogs.com/yongfa365/archive/2010/05/10/NPOI-MyXls-DataTable-To-Excel-From-Excel.html