NPOI帮助类（Excel转DataTable、DataTable转Excel）

  1 using System;
  2 using System.Collections.Generic;
  3 using System.Linq;
  4 using System.Text;
  5 using NPOI.SS.UserModel;
  6 using NPOI.XSSF.UserModel;
  7 using NPOI.HSSF.UserModel;
  8 using System.IO;
  9 using System.Data;
 10
 11 namespace NetUtilityLib
 12 {
 13     public class ExcelHelper : IDisposable
 14     {
 15         private string fileName = null; //文件名
 16         private IWorkbook workbook = null;
 17         private FileStream fs = null;
 18         private bool disposed;
 19
 20         public ExcelHelper(string fileName)
 21         {
 22             this.fileName = fileName;
 23             disposed = false;
 24         }
 25
 26         /// <summary>
 27         /// 将DataTable数据导入到excel中
 28         /// </summary>
 29         /// <param name="data">要导入的数据</param>
 30         /// <param name="isColumnWritten">DataTable的列名是否要导入</param>
 31         /// <param name="sheetName">要导入的excel的sheet的名称</param>
 32         /// <returns>导入数据行数(包含列名那一行)</returns>
 33         public int DataTableToExcel(DataTable data, string sheetName, bool isColumnWritten)
 34         {
 35             int i = 0;
 36             int j = 0;
 37             int count = 0;
 38             ISheet sheet = null;
 39
 40             fs = new FileStream(fileName, FileMode.OpenOrCreate, FileAccess.ReadWrite);
 41             if (fileName.IndexOf(".xlsx") > 0) // 2007版本
 42                 workbook = new XSSFWorkbook();
 43             else if (fileName.IndexOf(".xls") > 0) // 2003版本
 44                 workbook = new HSSFWorkbook();
 45
 46             try
 47             {
 48                 if (workbook != null)
 49                 {
 50                     sheet = workbook.CreateSheet(sheetName);
 51                 }
 52                 else
 53                 {
 54                     return -1;
 55                 }
 56
 57                 if (isColumnWritten == true) //写入DataTable的列名
 58                 {
 59                     IRow row = sheet.CreateRow(0);
 60                     for (j = 0; j < data.Columns.Count; ++j)
 61                     {
 62                         row.CreateCell(j).SetCellValue(data.Columns[j].ColumnName);
 63                     }
 64                     count = 1;
 65                 }
 66                 else
 67                 {
 68                     count = 0;
 69                 }
 70
 71                 for (i = 0; i < data.Rows.Count; ++i)
 72                 {
 73                     IRow row = sheet.CreateRow(count);
 74                     for (j = 0; j < data.Columns.Count; ++j)
 75                     {
 76                         row.CreateCell(j).SetCellValue(data.Rows[i][j].ToString());
 77                     }
 78                     ++count;
 79                 }
 80                 workbook.Write(fs); //写入到excel
 81                 return count;
 82             }
 83             catch (Exception ex)
 84             {
 85                 Console.WriteLine("Exception: " + ex.Message);
 86                 return -1;
 87             }
 88         }
 89
 90         /// <summary>
 91         /// 将excel中的数据导入到DataTable中
 92         /// </summary>
 93         /// <param name="sheetName">excel工作薄sheet的名称</param>
 94         /// <param name="isFirstRowColumn">第一行是否是DataTable的列名</param>
 95         /// <returns>返回的DataTable</returns>
 96         public DataTable ExcelToDataTable(string sheetName, bool isFirstRowColumn)
 97         {
 98             ISheet sheet = null;
 99             DataTable data = new DataTable();
100             int startRow = 0;
101             try
102             {
103                 fs = new FileStream(fileName, FileMode.Open, FileAccess.Read);
104                 if (fileName.IndexOf(".xlsx") > 0) // 2007版本
105                     workbook = new XSSFWorkbook(fs);
106                 else if (fileName.IndexOf(".xls") > 0) // 2003版本
107                     workbook = new HSSFWorkbook(fs);
108
109                 if (sheetName != null)
110                 {
111                     sheet = workbook.GetSheet(sheetName);
112                     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
113                     {
114                         sheet = workbook.GetSheetAt(0);
115                     }
116                 }
117                 else
118                 {
119                     sheet = workbook.GetSheetAt(0);
120                 }
121                 if (sheet != null)
122                 {
123                     IRow firstRow = sheet.GetRow(0);
124                     int cellCount = firstRow.LastCellNum; //一行最后一个cell的编号 即总的列数
125
126                     if (isFirstRowColumn)
127                     {
128                         for (int i = firstRow.FirstCellNum; i < cellCount; ++i)
129                         {
130                             ICell cell = firstRow.GetCell(i);
131                             if (cell != null)
132                             {
133                                 string cellValue = cell.StringCellValue;
134                                 if (cellValue != null)
135                                 {
136                                     DataColumn column = new DataColumn(cellValue);
137                                     data.Columns.Add(column);
138                                 }
139                             }
140                         }
141                         startRow = sheet.FirstRowNum + 1;
142                     }
143                     else
144                     {
145                         startRow = sheet.FirstRowNum;
146                     }
147
148                     //最后一列的标号
149                     int rowCount = sheet.LastRowNum;
150                     for (int i = startRow; i <= rowCount; ++i)
151                     {
152                         IRow row = sheet.GetRow(i);
153                         if (row == null) continue; //没有数据的行默认是null　　　　　　　
154
155                         DataRow dataRow = data.NewRow();
156                         for (int j = row.FirstCellNum; j < cellCount; ++j)
157                         {
158                             if (row.GetCell(j) != null) //同理，没有数据的单元格都默认是null
159                                 dataRow[j] = row.GetCell(j).ToString();
160                         }
161                         data.Rows.Add(dataRow);
162                     }
163                 }
164
165                 return data;
166             }
167             catch (Exception ex)
168             {
169                 Console.WriteLine("Exception: " + ex.Message);
170                 return null;
171             }
172         }
173
174         public void Dispose()
175         {
176             Dispose(true);
177             GC.SuppressFinalize(this);
178         }
179
180         protected virtual void Dispose(bool disposing)
181         {
182             if (!this.disposed)
183             {
184                 if (disposing)
185                 {
186                     if (fs != null)
187                         fs.Close();
188                 }
189
190                 fs = null;
191                 disposed = true;
192             }
193         }
194     }
195 }