C#中NPOI操作excel之读取和写入excel数

一、下载引用

下载需要引用的dll，即：NPOI.dll，NPOI.OOXML.dll，NPOI.OpenXml4Net.dll，ICSharpCode.SharpZipLib.dll（office2007版需要此dll）。

程序集下载地址：点击打开链接

二、excel转datatable类

 using System;
 using System.Data;
 using System.IO;
 using NPOI.SS.UserModel;
 using NPOI.XSSF.UserModel;
 using NPOI.HSSF.UserModel;

 namespace NPOIOprateExcel
 {
     public class ExcelUtility
     {
         ///
         /// 将excel导入到datatable
         ///
         /// excel路径
         /// 第一行是否是列名
         /// 返回datatable
         public static DataTable ExcelToDataTable(string filePath, bool isColumnName)
         {
             DataTable dataTable = null;
             FileStream fs = null;
             DataColumn column = null;
             DataRow dataRow = null;
             IWorkbook workbook = null;
             ISheet sheet = null;
             IRow row = null;
             ICell cell = null;
             int startRow = 0;
             try
             {
                 using (fs = File.OpenRead(filePath))
                 {
                     // 2007版本
                     if (filePath.IndexOf(".xlsx") > 0)
                         workbook = new XSSFWorkbook(fs);
                     // 2003版本
                     else if (filePath.IndexOf(".xls") > 0)
                         workbook = new HSSFWorkbook(fs);

                     if (workbook != null)
                     {
                         sheet = workbook.GetSheetAt(0);//读取第一个sheet，当然也可以循环读取每个sheet
                         dataTable = new DataTable();
                         if (sheet != null)
                         {
                             int rowCount = sheet.LastRowNum;//总行数
                             if (rowCount > 0)
                             {
                                 IRow firstRow = sheet.GetRow(0);//第一行
                                 int cellCount = firstRow.LastCellNum;//列数

                                 //构建datatable的列
                                 if (isColumnName)
                                 {
                                     startRow = 1;//如果第一行是列名，则从第二行开始读取
                                     for (int i = firstRow.FirstCellNum; i < cellCount; ++i)
                                     {
                                         cell = firstRow.GetCell(i);
                                         if (cell != null)
                                         {
                                             if (cell.StringCellValue != null)
                                             {
                                                 column = new DataColumn(cell.StringCellValue);
                                                 dataTable.Columns.Add(column);
                                             }
                                         }
                                     }
                                 }
                                 else
                                 {
                                     for (int i = firstRow.FirstCellNum; i < cellCount; ++i)
                                     {
                                         column = new DataColumn("column" + (i + 1));
                                         dataTable.Columns.Add(column);
                                     }
                                 }

                                 //填充行
                                 for (int i = startRow; i <= rowCount; ++i)
                                 {
                                     row = sheet.GetRow(i);
                                     if (row == null) continue;

                                     dataRow = dataTable.NewRow();
                                     for (int j = row.FirstCellNum; j < cellCount; ++j)
                                     {
                                         cell = row.GetCell(j);
                                         if (cell == null)
                                         {
                                             dataRow[j] = "";
                                         }
                                         else
                                         {
                                             //CellType(Unknown = -1,Numeric = 0,String = 1,Formula = 2,Blank = 3,Boolean = 4,Error = 5,)
                                             switch (cell.CellType)
                                             {
                                                 case CellType.Blank:
                                                     dataRow[j] = "";
                                                     break;
                                                 case CellType.Numeric:
                                                     short format = cell.CellStyle.DataFormat;
                                                     //对时间格式（2015.12.5、2015/12/5、2015-12-5等）的处理
                                                     if (format == 14 || format == 31 || format == 57 || format == 58)
                                                         dataRow[j] = cell.DateCellValue;
                                                     else
                                                         dataRow[j] = cell.NumericCellValue;
                                                     break;
                                                 case CellType.String:
                                                     dataRow[j] = cell.StringCellValue;
                                                     break;
                                             }
                                         }
                                     }
                                     dataTable.Rows.Add(dataRow);
                                 }
                             }
                         }
                     }
                 }
                 return dataTable;
             }
             catch (Exception)
             {
                 if (fs != null)
                 {
                     fs.Close();
                 }
                 return null;
             }
         }
     }
 }

三、结果

四、写入excel类

 public static bool DataTableToExcel(DataTable dt)
         {
             bool result = false;
             IWorkbook workbook = null;
             FileStream fs = null;
             IRow row = null;
             ISheet sheet = null;
             ICell cell = null;
             try
             {
                 if (dt != null && dt.Rows.Count > 0)
                 {
                     workbook = new HSSFWorkbook();
                     sheet = workbook.CreateSheet("Sheet0");//创建一个名称为Sheet0的表
                     int rowCount = dt.Rows.Count;//行数
                     int columnCount = dt.Columns.Count;//列数

                     //设置列头
                     row = sheet.CreateRow(0);//excel第一行设为列头
                     for (int c = 0; c < columnCount; c++)
                     {
                         cell = row.CreateCell(c);
                         cell.SetCellValue(dt.Columns[c].ColumnName);
                     }

                     //设置每行每列的单元格,
                     for (int i = 0; i
                     {
                         row = sheet.CreateRow(i+1);
                         for (int j = 0; j < columnCount; j++)
                         {
                             cell = row.CreateCell(j);//excel第二行开始写入数据
                             cell.SetCellValue(dt.Rows[i][j].ToString());
                         }
                     }
                     using (fs = File.OpenWrite(@"D:/myxls.xls"))
                     {
                         workbook.Write(fs);//向打开的这个xls文件中写入数据
                         result = true;
                     }
                 }
                 return result;
             }
             catch (Exception ex)
             {
                 if (fs != null)
                 {
                     fs.Close();
                 }
                 return false;
             }
         }

结果如下