使用NPOI导出，读取EXCEL（可追加功能）

使用NPOI导出，读取EXCEL，具有可追加功能

看代码

  1 using System;
  2 using System.Collections.Generic;
  3 using System.Text;
  4 using System.IO;
  5 using System.Data;
  6 using NPOI.SS.UserModel;
  7 using NPOI.XSSF.UserModel;
  8 using NPOI.HSSF.UserModel;
  9 
 10 namespace NPOIExcel
 11 {
 12     public class ExcelEX
 13     {
 14 
 15         /// 

 16         /// 将DataTable数据导入到excel中
 17         /// 
 18         /// 文件名
 19         /// 要导入的数据
 20         /// 要导入的excel的sheet的名称
 21         /// 是否是追加模式
 22         /// DataTable的列名是否要导入
 23         /// 导入数据行数(包含列名那一行)
 24         public static int DataTableToExcel(string fileName, DataTable data, bool blnAppled = false, string sheetName = "sheet1", bool isColumnWritten = true)
 25         {
 26             int i = 0;
 27             int j = 0;
 28             int count = 0;
 29             ISheet sheet = null;
 30             IWorkbook workbook = null;
 31             using (FileStream fs = new FileStream(fileName, FileMode.OpenOrCreate, FileAccess.ReadWrite))
 32             {
 33                 if (!blnAppled)
 34                 {
 35                     if (fileName.IndexOf(".xlsx") > 0) // 2007版本
 36                         workbook = new XSSFWorkbook();
 37                     else if (fileName.IndexOf(".xls") > 0) // 2003版本
 38                         workbook = new HSSFWorkbook();
 39                 }
 40                 else
 41                 {
 42                     if (fileName.IndexOf(".xlsx") > 0) // 2007版本
 43                         workbook = new XSSFWorkbook(fs);
 44                     else if (fileName.IndexOf(".xls") > 0) // 2003版本
 45                         workbook = new HSSFWorkbook(fs);
 46                 }
 47 
 48                 try
 49                 {
 50                     if (!blnAppled && !string.IsNullOrEmpty(sheetName))
 51                     {
 52                         if (workbook != null)
 53                         {
 54                             sheet = workbook.CreateSheet(sheetName);
 55                         }
 56                         else
 57                         {
 58                             return -1;
 59                         }
 60                     }
 61                     else
 62                     {
 63                         sheet = workbook.GetSheetAt(0);
 64                     }
 65 
 66                     if (!blnAppled)
 67                     {
 68                         if (isColumnWritten == true) //写入DataTable的列名
 69                         {
 70                             IRow row = sheet.CreateRow(0);
 71                             for (j = 0; j < data.Columns.Count; ++j)
 72                             {
 73                                 row.CreateCell(j).SetCellValue(data.Columns[j].ColumnName);
 74                             }
 75                             count = 1;
 76                         }
 77                         else
 78                         {
 79                             count = 0;
 80                         }
 81                     }
 82 
 83                     count = sheet.LastRowNum + 1;
 84 
 85                     for (i = 0; i < data.Rows.Count; ++i)
 86                     {
 87                         IRow row = sheet.CreateRow(count);
 88                         for (j = 0; j < data.Columns.Count; ++j)
 89                         {
 90                             row.CreateCell(j).SetCellValue(data.Rows[i][j].ToString());
 91                         }
 92                         ++count;
 93                     }
 94                    
 95                 }
 96                 catch (Exception ex)
 97                 {
 98                     Console.WriteLine("Exception: " + ex.Message);
 99                     return -1;
100                 }
101             }
102 
103             FileStream outFs = new FileStream(fileName, FileMode.Open);
104             workbook.Write(outFs);
105             outFs.Close();            
106             return count;
107         }
108 
109         /// 

110         /// 将excel中的数据导入到DataTable中
111         /// 
112         /// excel工作薄sheet的名称
113         /// 第一行是否是DataTable的列名
114         /// 返回的DataTable
115         public static DataTable ExcelToDataTable(string fileName, string sheetName = null, bool isFirstRowColumn = true)
116         {
117             ISheet sheet = null;
118             DataTable data = new DataTable();
119             int startRow = 0;
120             IWorkbook workbook = null;
121             try
122             {
123                 FileStream fs = new FileStream(fileName, FileMode.Open, FileAccess.Read);
124                 if (fileName.IndexOf(".xlsx") > 0) // 2007版本
125                     workbook = new XSSFWorkbook(fs);
126                 else if (fileName.IndexOf(".xls") > 0) // 2003版本
127                     workbook = new HSSFWorkbook(fs);
128 
129                 if (sheetName != null)
130                 {
131                     sheet = workbook.GetSheet(sheetName);
132                     if (sheet == null) //如果没有找到指定的sheetName对应的sheet，则尝试获取第一个sheet
133                     {
134                         sheet = workbook.GetSheetAt(0);
135                     }
136                 }
137                 else
138                 {
139                     sheet = workbook.GetSheetAt(0);
140                 }
141                 if (sheet != null)
142                 {
143                     IRow firstRow = sheet.GetRow(0);
144                     int cellCount = firstRow.LastCellNum; //一行最后一个cell的编号 即总的列数
145 
146                     if (isFirstRowColumn)
147                     {
148                         for (int i = firstRow.FirstCellNum; i < cellCount; ++i)
149                         {
150                             ICell cell = firstRow.GetCell(i);
151                             if (cell != null)
152                             {
153                                 string cellValue = cell.StringCellValue;
154                                 if (cellValue != null)
155                                 {
156                                     DataColumn column = new DataColumn(cellValue);
157                                     data.Columns.Add(column);
158                                 }
159                             }
160                         }
161                         startRow = sheet.FirstRowNum + 1;
162                     }
163                     else
164                     {
165                         startRow = sheet.FirstRowNum;
166                     }
167 
168                     //最后一列的标号
169                     int rowCount = sheet.LastRowNum;
170                     for (int i = startRow; i <= rowCount; ++i)
171                     {
172                         IRow row = sheet.GetRow(i);
173                         if (row == null) continue; //没有数据的行默认是null　　　　　　　
174 
175                         DataRow dataRow = data.NewRow();
176                         for (int j = row.FirstCellNum; j < cellCount; ++j)
177                         {
178                             if (row.GetCell(j) != null) //同理，没有数据的单元格都默认是null
179                                 dataRow[j] = row.GetCell(j).ToString();
180                         }
181                         data.Rows.Add(dataRow);
182                     }
183                 }
184 
185                 return data;
186             }
187             catch (Exception ex)
188             {
189                 Console.WriteLine("Exception: " + ex.Message);
190                 return null;
191             }
192         }
193 
194 
195     }
196 }

View Code

看测试

 1 using System;
 2 using System.Collections.Generic;
 3 using System.Linq;
 4 using System.Text;
 5 using System.Data;
 6 using NPOIExcel;
 7 
 8 namespace Test
 9 {
10     class Program
11     {
12         static void Main(string[] args)
13         {
14             DataTable dt = new DataTable();
15             dt.Columns.Add("A", typeof(string));
16             dt.Columns.Add("B", typeof(string));
17             dt.Columns.Add("C", typeof(string));
18             for (int i = 0; i < 50; i++)
19             {
20                 DataRow dr = dt.NewRow();
21                 for (int j = 0; j < 3; j++)
22                 {
23                     dr[j] = "1_" + i.ToString() + "_" + j.ToString();
24                 }
25                 dt.Rows.Add(dr);
26             }
27             ExcelEX.DataTableToExcel("d:\\123.xlsx",dt);
28             dt.Rows.Clear();
29 
30             for (int i = 0; i < 50; i++)
31             {
32                 DataRow dr = dt.NewRow();
33                 for (int j = 0; j < 3; j++)
34                 {
35                     dr[j] = "2_" + i.ToString() + "_" + j.ToString();
36                 }
37                 dt.Rows.Add(dr);
38             }
39 
40             ExcelEX.DataTableToExcel("d:\\123.xlsx", dt,true);
41             Console.ReadKey();
42         }
43     }
44 }

View Code

看结果