NPOI Excel导入 导出

using NPOI.HSSF.UserModel;
using NPOI.SS.UserModel;
using System;
using System.Collections.Generic;
using System.Data;
using System.IO;
using System.Text;

 1  public DataSet ExcelToDataTable(string path)
 2         {
 3             DataSet dataSet1 = new DataSet();
 4             HSSFWorkbook hssfworkbook;
 5             using (FileStream file = new FileStream(path, FileMode.Open, FileAccess.Read))
 6             {
 7                 hssfworkbook = new HSSFWorkbook(file); //把xls文件中的数据写入hssfworkbook中
 8 
 9 
10                 //for (int i = 0; i < hssfworkbook.NumberOfSheets; i++)  //NumberOfSheets是myxls.xls中总共的表数
11                 //{
12                 ISheet sheet = hssfworkbook.GetSheetAt(0);   //读取当前表数据
13 
14                 DataTable dt = new DataTable();
15 
16                 for (int j = 0; j <= sheet.LastRowNum; j++)  //LastRowNum 是当前表的总行数
17                 {
18                     IRow row = sheet.GetRow(j);  //读取当前行数据
19                     DataRow dr = dt.NewRow();
20                     if (row != null)
21                     {
22                         //sbr.Append("-------------------------------------\r\n"); //读取行与行之间的提示界限
23                         for (int k = 0; k < row.LastCellNum; k++)  //LastCellNum 是当前行的总列数
24                         {
25                             ICell cell = row.GetCell(k);  //当前表格
26                             if (cell != null)
27                             {
28                                 if (j == 0)
29                                 {
30                                     dt.Columns.Add(cell.ToString());
31                                 }
32                                 else
33                                 {
34                                     RegexHelper regexHelper = new RegexHelper();
35 
36                                     if (regexHelper.IsMatch(cell.ToString(), "[0-9]{1,2}/[0-9]{1,2}/[0-9]{2,4}"))
37                                     {
38                                         dr[k] = cell.DateCellValue.ToString();
39                                     }
40                                     else
41                                     {
42                                         dr[k] = cell.ToString();
43                                     }
44                                     //日期格式判断输出
45 
46                                 }
47                                 //sbr.Append(cell.ToString());   //获取表格中的数据并转换为字符串类型
48 
49                             }
50                         }//for
51                     }// if (row != null)
52                     if (j != 0)
53                     {
54                         dt.Rows.Add(dr);
55                     }
56                 }//for j
57 
58                 dataSet1.Tables.Add(dt);
59 
60                 //}
61 
62             }//using
63             return dataSet1;
64         }

 1 #region "数据导出"
 2         /// <summary>
 3         /// WinForm DataTable数据导出Excel到本地
 4         /// </summary>
 5         /// <param name="table"></param>
 6         /// <param name="fileName"></param>
 7         public static void SaveToFile(DataTable table, string fileName)
 8         {
 9             using (FileStream fs = new FileStream(fileName, FileMode.Create, FileAccess.Write))
10             {
11                 MemoryStream ms = RenderToExcel(table);
12 
13                 byte[] data = ms.ToArray();
14 
15                 fs.Write(data, 0, data.Length);
16                 fs.Flush();
17 
18                 data = null;
19             }
20         }
21         public static MemoryStream RenderToExcel(DataTable table)
22         {
23             MemoryStream ms = new MemoryStream();
24 
25             using (table)
26             {
27                 using (IWorkbook workbook = new HSSFWorkbook())
28                 {
29                     using (ISheet sheet = workbook.CreateSheet())
30                     {
31                         IRow headerRow = sheet.CreateRow(0);
32 
33                         // 处理标题.
34                         foreach (DataColumn column in table.Columns)
35                             headerRow.CreateCell(column.Ordinal).SetCellValue(column.Caption);//如果标题没有设置,返回ColumnName的值
36 
37 
38                         int rowIndex = 1;
39 
40                         foreach (DataRow row in table.Rows)
41                         {
42                             IRow dataRow = sheet.CreateRow(rowIndex);
43 
44                             foreach (DataColumn column in table.Columns)
45                             {
46                                 dataRow.CreateCell(column.Ordinal).SetCellValue(row[column].ToString());
47                             }
48 
49                             rowIndex++;
50                         }
51 
52                         workbook.Write(ms);
53                         ms.Flush();
54                         ms.Position = 0;
55                     }
56                 }
57             }
58             return ms;
59         }
60 
61         /// <summary>
62         /// Web DataTable 数据导出到浏览器客户端
63         /// </summary>
64         /// <param name="table"></param>
65         /// <param name="context"></param>
66         /// <param name="fileName"></param>
67         static void RenderToBrowser(DataTable table, HttpContext context, string fileName)
68         {
69             MemoryStream ms = RenderToExcel(table);
70             if (context.Request.Browser.Browser == "IE")
71                 fileName = HttpUtility.UrlEncode(fileName);
72             context.Response.AddHeader("Content-Disposition", "attachment;fileName=" + fileName);
73             context.Response.BinaryWrite(ms.ToArray());
74         }
75 
76         #endregion

 1  ExcelHelp ExcelHelp = new ExcelHelp();
 2             //导入Excel到datagridview
 3             dataGridView1.DataSource = ExcelHelp.ExcelToDataTable(txtfileurl.Text).Tables[0];
 4             //导出
 5             saveFileDialog1.Filter = "Excel|*.Xls;";
 6             saveFileDialog1.FileName = "测试.Xls";
 7             if (saveFileDialog1.ShowDialog() == DialogResult.OK)
 8             {
 9                 ExcelHelp.SaveToFile(rptDst.Tables["interaction"], saveFileDialog1.FileName);
10             }