C# NOPI 项目实战(经典)(可下载项目源码)

1 -.首先说明下项目目的:

    之前我有写过一篇  "NPOI操作EXCEL" 

 

这篇文章主要介绍了如何安装NPOI，以及NPOI具体如何使用，并且用具体实例介绍了excel导入到datagridview以及 datagridview如何导出到excel并保存。如果不清楚这块的去我公众号去搜索这篇文章阅读。

      今天这篇文章主要是实现多个excel多张表格的合并，这个是我们数据处理时候经常使用的一个功能，其实最佳的途径是用excel自带的power query（excel2016自带，excel2016以下版本需要安装插件），用这个功能你甚至不需要写一句代码，就可以轻轻松松实现百万计甚至千万级数据操作，当然你也可以用excel里面的vba，这些都可以，但是这不是今天要将的内容，今天的内容就是要用C# 实现数据表格的合并。

2. 源码:

npoi.cs

using System;using System.Collections.Generic;using NPOI.HSSF.UserModel;using NPOI.SS.UserModel;using NPOI.XSSF.UserModel;using System.Data;using System.IO;namespace npoi1{ public class NPOIExcel {  /// <summary>  /// 将excel导入到datatable  /// </summary>  /// <param name="filePath">excel路径</param>  /// <param name="isColumnName">第一行是否是列名</param>  /// <returns>返回datatable</returns>  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;   }  }  /// <summary>  /// 写入excel  /// </summary>  /// <param name="dt">datatable</param>  /// <param name="strFile">strFile</param>  /// <returns></returns>  public static bool DataTableToExcel(DataTable dt, string strFile)  {   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 XSSFWorkbook();//HSSFWorkbook:是操作Excel2003以前（包括2003）的版本，扩展名是.xls XSSFWorkbook:是操作Excel2007的版本，扩展名是.xlsx     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 < rowCount; 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(strFile))     {      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();    }    Console.WriteLine(ex.StackTrace + ex.Message);    return false;   }  }  /// <summary>  /// Excel导入成Datable  /// </summary>  /// <param name="file">导入路径(包含文件名与扩展名)</param>  /// <returns></returns>  public static DataTable ExcelToTable(string file ,int nSheet)  {   DataTable dt = new DataTable();   IWorkbook workbook;   string fileExt = Path.GetExtension(file).ToLower();   using (FileStream fs = new FileStream(file, FileMode.Open, FileAccess.Read))   {    //XSSFWorkbook 适用XLSX格式，HSSFWorkbook 适用XLS格式    if (fileExt == ".xlsx") { workbook = new XSSFWorkbook(fs); } else if (fileExt == ".xls") { workbook = new HSSFWorkbook(fs); } else { workbook = null; }    if (workbook == null) { return null; }    ISheet sheet = null;    if (nSheet < workbook.NumberOfSheets) //为了不让获取超过表格数量最大索引导致报错     sheet = workbook.GetSheetAt(nSheet);    else    { return null; }    //表头    IRow header = sheet.GetRow(sheet.FirstRowNum);    List<int> columns = new List<int>();    for (int i = 0; i < header.LastCellNum; i++)    {     object obj = GetValueType(header.GetCell(i));     if (obj == null || obj.ToString() == string.Empty)     {      dt.Columns.Add(new DataColumn("Columns" + i.ToString()));     }     else      dt.Columns.Add(new DataColumn(obj.ToString()));     columns.Add(i);    }    //数据    for (int i = sheet.FirstRowNum + 1; i <= sheet.LastRowNum; i++)    {     DataRow dr = dt.NewRow();     bool hasValue = false;     foreach (int j in columns)     {      dr[j] = GetValueType(sheet.GetRow(i).GetCell(j));      if (dr[j] != null && dr[j].ToString() != string.Empty)      {       hasValue = true;      }     }     if (hasValue)     {      dt.Rows.Add(dr);     }    }   }   return dt;  }  /// <summary>  /// Datable导出成Excel  /// </summary>  /// <param name="dt"></param>  /// <param name="file">导出路径(包括文件名与扩展名)</param>  public static void TableToExcel(DataTable[] dt, string file , int nSheet)  {   IWorkbook workbook;   string fileExt = Path.GetExtension(file).ToLower();   if (fileExt == ".xlsx") { workbook = new XSSFWorkbook(); } else if (fileExt == ".xls") { workbook = new HSSFWorkbook(); } else { workbook = null; }   if (workbook == null) { return; }   ISheet[] sheet = new ISheet[nSheet];   for (int k = 0; k < nSheet; k++)   {    if (dt[k] != null)    {     sheet[k] = string.IsNullOrEmpty(dt[k].TableName) ? workbook.CreateSheet("Sheet" + (k + 1).ToString()) : workbook.CreateSheet(dt[k].TableName);     //表头     IRow row = sheet[k].CreateRow(0);     for (int i = 0; i < dt[k].Columns.Count; i++)     {      ICell cell = row.CreateCell(i);      cell.SetCellValue(dt[k].Columns[i].ColumnName);     }     //数据     for (int i = 0; i < dt[k].Rows.Count; i++)     {      IRow row1 = sheet[k].CreateRow(i + 1);      for (int j = 0; j < dt[k].Columns.Count; j++)      {       ICell cell = row1.CreateCell(j);       cell.SetCellValue(dt[k].Rows[i][j].ToString());      }     }    }    else     continue;   }       //转为字节数组   MemoryStream stream = new MemoryStream();   workbook.Write(stream);   var buf = stream.ToArray();   //保存为Excel文件   using (FileStream fs = new FileStream(file, FileMode.Create, FileAccess.Write))   {    fs.Write(buf, 0, buf.Length);    fs.Flush();   }  }  /// <summary>  /// 获取单元格类型  /// </summary>  /// <param name="cell"></param>  /// <returns></returns>  private static object GetValueType(ICell cell)  {   if (cell == null)    return null;   switch (cell.CellType)   {    case CellType.Blank: //BLANK:     return null;    case CellType.Boolean: //BOOLEAN:     return cell.BooleanCellValue;    case CellType.Numeric: //NUMERIC:     return cell.NumericCellValue;    case CellType.String: //STRING:     return cell.StringCellValue;    case CellType.Error: //ERROR:     return cell.ErrorCellValue;    case CellType.Formula: //FORMULA:    default:     return "=" + cell.CellFormula;   }  } }}

　　mainForm.cs

using NPOI.SS.UserModel;using System;using System.Data;using System.Diagnostics;using System.IO;using System.Windows.Forms;namespace npoi1{ public partial class mainForm : Form {  public mainForm()  {   InitializeComponent();  }  private void Form1_Load(object sender, EventArgs e)  {  }  public static int sheetCount=5;//定义表的最大数量  DataTable[] lastTable = new DataTable[sheetCount];  private void button1_Click(object sender, EventArgs e)  {   Stopwatch sw = new Stopwatch();   sw.Start();   //dataGridView1.DataSource = NPOIExcel.ExcelToDataTable("电脑统计表.xlsx", true);//方式1   DataTable[] tempTable = new DataTable[sheetCount];   DirectoryInfo dir = new DirectoryInfo(@"C:\Users\TPS20\Desktop\excel\");   for (int i = 0; i < sheetCount; i++) //遍历一个excel的每个sheet   {    bool flag = true;    foreach (FileInfo dChild in dir.GetFiles("*.xlsx"))//遍历文件夹下的xlsx文件    {     tempTable[i] = NPOIExcel.ExcelToTable(dChild.FullName, i);//方式2     if (flag && lastTable[i] == null&& tempTable[i] != null) //第一次直接赋值，使得lastTable[i]获取表结构不为null     {      lastTable[i] = tempTable[i];      flag = false;     }     if (tempTable[i]!=null)     GetAllDataTable(tempTable[i] , i);//DataTable合并    }       }   NPOIExcel.TableToExcel(lastTable, @"C:\Users\TPS20\Desktop\excel\1\111.xlsx", sheetCount);//方式2   dataGridView1.DataSource = lastTable[0];//调试时候显示用的，可以去掉   dataGridView2.DataSource = lastTable[1];//调试时候显示用的，可以去掉   dataGridView3.DataSource = lastTable[2];//调试时候显示用的，可以去掉   sw.Stop();   label1.Text = sw.ElapsedMilliseconds.ToString("数据导入耗时：" + "0000"+"ms");   MessageBox.Show("数据导入完成");  }  public void GetAllDataTable(DataTable dt,int nSheet)  {   if(lastTable[nSheet]!=null)   lastTable[nSheet].Merge(dt, false, MissingSchemaAction.AddWithKey);  }  private void dataGridView1_RowsAdded(object sender, DataGridViewRowsAddedEventArgs e)  {   for (int i = 0; i < dataGridView1.Rows.Count; i++)    this.dataGridView1.Rows[i].HeaderCell.Value = (i + 1).ToString();  }  private void button2_Click(object sender, EventArgs e)  {   //Stopwatch sw = new Stopwatch();   //sw.Start();   //DataTable dt = (dataGridView1.DataSource as DataTable);   ////NPOIExcel.DataTableToExcel(dt, "d:\\111.xlsx");//方式1   //NPOIExcel.TableToExcel(dt, "d:\\111.xlsx",0);//方式2   //sw.Stop();   //label2.Text = sw.ElapsedMilliseconds.ToString("数据导出耗时：" + "0000" + "ms");   //MessageBox.Show("数据导出完成");  } }}

　　3. 运行效果

 

 

4.源码百度网盘下载地址：

 

链接：https://pan.baidu.com/s/1L0rv_CM0N4FTZ-fpwS-YXA 

提取码：cjj8 

想了解更多C#知识，请扫描下方公众号二维码

 

 

需加微信交流群的，请加小编微信号z438679770，切记备注 加群，小编将会第一时间邀请你进群！

原文转载：http://www.shaoqun.com/a/577603.html

跨境电商：https://www.ikjzd.com/

cicpa：https://www.ikjzd.com/w/1375

亿恩：https://www.ikjzd.com/w/1461

1-.首先说明下项目目的:之前我有写过一篇"NPOI操作EXCEL"这篇文章主要介绍了如何安装NPOI，以及NPOI具体如何使用，并且用具体实例介绍了excel导入到datagridview以及datagridview如何导出到excel并保存。如果不清楚这块的去我公众号去搜索这篇文章阅读。今天这篇文章主要是实现多个excel多张表格的合并，这个是我们数据处理时候经常使用的一个
万国邮政联盟：https://www.ikjzd.com/w/861
淘粉8：https://www.ikjzd.com/w/1725.html
outfit：https://www.ikjzd.com/w/938
口述：无耻闺蜜誓死做情敌 霸占我男友：http://lady.shaoqun.com/m/a/10742.html
KW递增工具集锦：https://www.ikjzd.com/tl/10245
亲测，最新直评政策整理12点：https://www.ikjzd.com/tl/5267