一、NPOI介绍:
使用 NPOI 你就可以在没有安装 Office 或者相应环境的机器上对 WORD/EXCEL 文档进行读写。NPOI是构建在POI 3.x版本之上的,它可以在没有安装Office的情况下对Word/Excel文档进行读写操作
二、安装NPOI
新建控制台应用程序>管理NuGet程序包>搜索NPOI>安装NPOI
三.下面是我需要的读取的Excel文件,数据格式如下:
四.添加ExcelHelper类:
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- using System;
- using NPOI.SS.UserModel;
- using NPOI.XSSF.UserModel;
- using NPOI.HSSF.UserModel;
- using System.IO;
- using System.Data;
- namespace NPOI.ReadExcel
- {
- public class ExcelHelper : IDisposable
- {
- private string fileName = null; //文件名
- private IWorkbook workbook = null;
- private FileStream fs = null;
- private bool disposed;
- public ExcelHelper(string fileName)
- {
- this.fileName = fileName;
- disposed = false;
- }
- /// <summary>
- /// 将DataTable数据导入到excel中
- /// </summary>
- /// <param name="data">要导入的数据</param>
- /// <param name="isColumnWritten">DataTable的列名是否要导入</param>
- /// <param name="sheetName">要导入的excel的sheet的名称</param>
- /// <returns>导入数据行数(包含列名那一行)</returns>
- public int DataTableToExcel(DataTable data, string sheetName, bool isColumnWritten)
- {
- int i = 0;
- int j = 0;
- int count = 0;
- ISheet sheet = null;
- fs = new FileStream(fileName, FileMode.OpenOrCreate, FileAccess.ReadWrite);
- if (fileName.IndexOf(".xlsx") > 0) // 2007版本
- workbook = new XSSFWorkbook();
- else if (fileName.IndexOf(".xls") > 0) // 2003版本
- workbook = new HSSFWorkbook();
- try
- {
- if (workbook != null)
- {
- sheet = workbook.CreateSheet(sheetName);
- }
- else
- {
- return -1;
- }
- if (isColumnWritten == true) //写入DataTable的列名
- {
- IRow row = sheet.CreateRow(0);
- for (j = 0; j < data.Columns.Count; ++j)
- {
- row.CreateCell(j).SetCellValue(data.Columns[j].ColumnName);
- }
- count = 1;
- }
- else
- {
- count = 0;
- }
- for (i = 0; i < data.Rows.Count; ++i)
- {
- IRow row = sheet.CreateRow(count);
- for (j = 0; j < data.Columns.Count; ++j)
- {
- row.CreateCell(j).SetCellValue(data.Rows[i][j].ToString());
- }
- ++count;
- }
- workbook.Write(fs); //写入到excel
- return count;
- }
- catch (Exception ex)
- {
- Console.WriteLine("Exception: " + ex.Message);
- return -1;
- }
- }
- /// <summary>
- /// 将excel中的数据导入到DataTable中
- /// </summary>
- /// <param name="sheetName">excel工作薄sheet的名称</param>
- /// <param name="isFirstRowColumn">第一行是否是DataTable的列名</param>
- /// <returns>返回的DataTable</returns>
- public DataTable ExcelToDataTable(string sheetName, bool isFirstRowColumn)
- {
- ISheet sheet = null;
- DataTable data = new DataTable();
- int startRow = 0;
- try
- {
- fs = new FileStream(fileName, FileMode.Open, FileAccess.Read);
- if (fileName.IndexOf(".xlsx") > 0) // 2007版本
- workbook = new XSSFWorkbook(fs);
- else if (fileName.IndexOf(".xls") > 0) // 2003版本
- workbook = new HSSFWorkbook(fs);
- if (sheetName != null)
- {
- sheet = workbook.GetSheet(sheetName);
- 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
- {
- sheet = workbook.GetSheetAt(0);
- }
- }
- else
- {
- sheet = workbook.GetSheetAt(0);
- }
- if (sheet != null)
- {
- IRow firstRow = sheet.GetRow(0);
- int cellCount = firstRow.LastCellNum; //一行最后一个cell的编号 即总的列数
- if (isFirstRowColumn)
- {
- for (int i = firstRow.FirstCellNum; i < cellCount; ++i)
- {
- ICell cell = firstRow.GetCell(i);
- if (cell != null)
- {
- string cellValue = cell.StringCellValue;
- if (cellValue != null)
- {
- DataColumn column = new DataColumn(cellValue);
- data.Columns.Add(column);
- }
- }
- }
- startRow = sheet.FirstRowNum + 1;
- }
- else
- {
- startRow = sheet.FirstRowNum;
- }
- //最后一列的标号
- int rowCount = sheet.LastRowNum;
- for (int i = startRow; i <= rowCount; ++i)
- {
- IRow row = sheet.GetRow(i);
- if (row == null) continue; //没有数据的行默认是null
- DataRow dataRow = data.NewRow();
- for (int j = row.FirstCellNum; j < cellCount; ++j)
- {
- if (row.GetCell(j) != null) //同理,没有数据的单元格都默认是null
- dataRow[j] = row.GetCell(j).ToString();
- }
- data.Rows.Add(dataRow);
- }
- }
- return data;
- }
- catch (Exception ex)
- {
- Console.WriteLine("Exception: " + ex.Message);
- return null;
- }
- }
- public void Dispose()
- {
- Dispose(true);
- GC.SuppressFinalize(this);
- }
- protected virtual void Dispose(bool disposing)
- {
- if (!this.disposed)
- {
- if (disposing)
- {
- if (fs != null)
- fs.Close();
- }
- fs = null;
- disposed = true;
- }
- }
- }
- }
五,读取文件到DataTable:
[csharp] view plain
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- using System;
- using System.Collections.Generic;
- using System.Data;
- using System.Linq;
- using System.Text;
- using System.Threading.Tasks;
- namespace NPOI.ReadExcel
- {
- class Program
- {
- static void Main(string[] args)
- {
- ExcelHelper excel_helper = new ExcelHelper(AppDomain.CurrentDomain.BaseDirectory + "test.xlsx");
- DataTable dt = excel_helper.ExcelToDataTable("",true);
- List<string> tableList=GetColumnsByDataTable(dt);
- for (int i = 0; i < tableList.Count; i++)
- {
- foreach (DataRow item in dt.Rows)
- {
- try
- {
- if (item[0].ToString() != "")
- {
- if (i < tableList.Count - 1 & item[i + 1].ToString()!="")
- {
- Console.WriteLine(item[0].ToString()+"\t"+item[i+1].ToString());
- }
- }
- }
- catch (Exception ex)
- { }
- }
- Console.WriteLine("");
- }
- Console.ReadKey();
- }
- /// <summary>
- /// 根据datatable获得列名
- /// </summary>
- /// <param name="dt">表对象</param>
- /// <returns>返回结果的数据列数组</returns>
- public static List<string> GetColumnsByDataTable(DataTable dt)
- {
- List<string> strColumns =new List<string> ();
- if (dt.Columns.Count > 0)
- {
- int columnNum = 0;
- columnNum = dt.Columns.Count;;
- for (int i = 0; i < dt.Columns.Count; i++)
- {
- strColumns.Add(dt.Columns[i].ColumnName);
- }
- }
- return strColumns;
- }
- }
- }
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