C# 操作Excel的多种方式

在项目开发过程和办公过程中，经常要遇到对Excel进行创建，读写等操作，excel太多师，整理也成了一大难题。通过程序对excel进行整理能快速提供开发和办公效率。

Excel操作几种方式

使用OleDb(过时)
使用Microsoft.Office.Interop.Excel COM组件(兼容性问题)
使用开源库NPOI(常用，操作丰富)
使用OpenXml(效率高)

使用OleDb

通过OleDb操作excel需要安装AccessDatabaseEngine组件，对Excel文件的格式有一定的限制，不支持一些特定的Excel功能。性能可能不如其他方法,比较老旧，基本不用。

       string excelFilePath = "D:\\Test\\test.xlsx";
       private void OpenExcelByOleDb()
       {
           string connectionString = $"Provider=Microsoft.ACE.OLEDB.12.0;Data Source={excelFilePath};Extended Properties='Excel 12.0;HDR=YES;'";
           using (OleDbConnection connection = new OleDbConnection(connectionString))
           {
               try
               {
                   connection.Open();
                   Console.WriteLine("链接成功!");

                   // 获取Excel文件中第一个工作表的数据
                   string query = "SELECT * FROM [Sheet1$]";
                   using (OleDbCommand command = new OleDbCommand(query, connection))
                   using (OleDbDataReader reader = command.ExecuteReader())
                   {
                       while (reader.Read())
                       {
                           // 假设第一列是字符串，第二列是整数
                           string stringValue = reader.GetString(0);
                           int intValue = reader.GetInt32(1);

                           Console.WriteLine($"String value: {stringValue}, Integer value: {intValue}");
                       }
                   }
               }
               catch (Exception ex)
               {
                   Console.WriteLine($"错误: {ex.Message}");
               }
           }
       }

Microsoft.Office.Interop.Excel

通过Microsoft.Office.Interop.Excel COM组件操作Excel可以实现对Excel文件的高度控制，支持复杂的Excel操作。但对资源的管理需要谨慎处理，易造成资源泄漏且兼容性不高。

        string excelFilePath = "D:\\Test\\test.xlsx";
        private void OpenExcelByInteropExcel()
        {
            // 创建Excel应用程序对象
            Excel.Application excelApp = new Excel.Application();
            excelApp.Visible = true; // 可见Excel应用程序界面

            // 打开Excel文件
            Excel.Workbook workbook = excelApp.Workbooks.Open(excelFilePath);
            Excel.Worksheet worksheet = workbook.Sheets[1] as Excel.Worksheet;

            // 读取或写入数据
            Excel.Range range = worksheet.UsedRange;
            for (int row = 1; row <= range.Rows.Count; row++)
            {
                for (int column = 1; column <= range.Columns.Count; column++)
                {
                    // 处理单元格数据
                    var cellValue = range.Cells[row, column].Value;
                    Console.WriteLine(cellValue.ToString());
                    //range.Cells[row, column].Value = 1;
                }
            }
            #region 保存模板
            //object Nothing = System.Reflection.Missing.Value;
            //Microsoft.Office.Interop.Excel.Workbook workbook1 = excelApp.Workbooks.Add(Nothing);
            //Microsoft.Office.Interop.Excel.Worksheet worksheet1 = (Microsoft.Office.Interop.Excel.Worksheet)workbook.Sheets["Sheet2"];//打开Sheet2
            //worksheet1.Copy(workbook1.Sheets["Sheet1"], Type.Missing);//复制模板Sheet1内容
            //workbook.Close(false, Type.Missing, Type.Missing);
            //workbook1.SaveAs("modelpath", Missing.Value, Missing.Value, Missing.Value, Missing.Value, Missing.Value, Microsoft.Office.Interop.Excel.XlSaveAsAccessMode.xlNoChange, Missing.Value, Missing.Value, Missing.Value, Missing.Value, Missing.Value);
            //workbook1.Close(false, Type.Missing, Type.Missing);
            #endregion

            // 释放资源
            workbook.Close(false);
            excelApp.Quit();
            System.Runtime.InteropServices.Marshal.ReleaseComObject(excelApp);
        }

使用开源库NPOI

使用开源库NPOI操作Excel跨平台，不依赖于Microsoft Office，适用于在服务器端等环境中操作Excel文件。支持读取和写入Excel文件，并提供了丰富的API。但对于复杂的Excel操作，不如COM组件灵活，无法实现一些高级功能。Nuget引用NPOI组件。

  string excelFilePath = "D:\\Test\\test.xlsx";
  private void OpenExcelByNPOI()
  {
      // 读取Excel文件
      using (FileStream fs = new FileStream(excelFilePath, FileMode.Open, FileAccess.Read))
      {
          IWorkbook workbook = new XSSFWorkbook(fs);
          ISheet sheet = workbook.GetSheetAt(0);

          // 遍历每一行
          for (int row = 0; row <= sheet.LastRowNum; row++)
          {
              IRow currentRow = sheet.GetRow(row);
              if (currentRow != null) // 确保行不为空
              {
                  // 遍历每一列
                  for (int column = 0; column < currentRow.LastCellNum; column++)
                  {
                      ICell currentCell = currentRow.GetCell(column);
                      if (currentCell != null) // 确保单元格不为空
                      {
                          // 处理单元格数据
                          var cellValue = currentCell.ToString();
                          Console.WriteLine(cellValue);
                      }
                  }
              }
          }
      }
  }

使用OpenXml

使用OpenXml操作Excel，它直接对文件流进行操作，而无需将整个文档加载到内存中，无需安装 Microsoft Office，非常适合服务器端应用程序和批处理。Nuget引用DocumentFormat.OpenXml 组件。

        string excelFilePath = "D:\\Test\\test.xlsx";
        private void OpenExcelByOpenXml()
        {
            //流式传输文件，性能高
            using (SpreadsheetDocument doc = SpreadsheetDocument.Open(excelFilePath, false))
            {
                WorkbookPart workbookPart = doc.WorkbookPart;
                Sheet sheet = workbookPart.Workbook.Sheets.GetFirstChild<Sheet>();
                WorksheetPart worksheetPart = (WorksheetPart)workbookPart.GetPartById(sheet.Id);

                OpenXmlReader reader = OpenXmlReader.Create(worksheetPart);
                while (reader.Read())
                {
                    if (reader.ElementType == typeof(DocumentFormat.OpenXml.Spreadsheet.Row))
                    {
                        DocumentFormat.OpenXml.Spreadsheet.Row row = (DocumentFormat.OpenXml.Spreadsheet.Row)reader.LoadCurrentElement();
                        foreach (DocumentFormat.OpenXml.Spreadsheet.Cell cell in row.Elements<DocumentFormat.OpenXml.Spreadsheet.Cell>())
                        {
                            string cellValue = GetCellValue(doc, cell);
                            Console.Write(cellValue + " ");
                        }
                        Console.WriteLine();
                    }
                }
            }

        }
        /// <summary>
        /// OpenXml获取单元格值
        /// 流式传输
        /// </summary>
        /// <param name="doc"></param>
        /// <param name="cell"></param>
        /// <returns></returns>
        private static string GetCellValue(SpreadsheetDocument doc, DocumentFormat.OpenXml.Spreadsheet.Cell cell)
        {
            SharedStringTablePart stringTablePart = doc.WorkbookPart.SharedStringTablePart;
            string value = cell.CellValue.InnerXml;

            if (cell.DataType != null && cell.DataType.Value == CellValues.SharedString)
            {
                return stringTablePart.SharedStringTable.ChildElements[Int32.Parse(value)].InnerText;
            }
            else
            {
                return value;
            }
        }

Excel与DatagridView之间操作

Excel文件导入DateGridView

  /// <summary>
  /// Excel导入DataGridView
  /// </summary>
  /// <param name="excelFilePath"></param>
  /// <param name="dataGridView"></param>
  public static void ImportExcelToDataGridView(string excelFilePath, DataGridView dataGridView)
  {
      Excel.Application excelApp = new Excel.Application();
      Excel.Workbook workbook = excelApp.Workbooks.Open(excelFilePath);
      Excel.Worksheet worksheet = workbook.Sheets[1];
      Range usedRange = worksheet.UsedRange;

      for (int i = 1; i <= usedRange.Columns.Count; i++)
      {
          DataGridViewColumn column = new DataGridViewColumn();
          column.Name = "Column" + i;
          column.HeaderText = "Column" + i;
          column.CellTemplate = new DataGridViewTextBoxCell();
          dataGridView.Columns.Add(column);
      }
      dataGridView.Rows.Clear();
      for (int i = 1; i <= usedRange.Rows.Count; i++)
      {
          DataGridViewRow row = new DataGridViewRow();
         
          for (int j = 1; j <= usedRange.Columns.Count; j++)
          {
              row.Cells.Add(new DataGridViewTextBoxCell());
              row.Cells[j - 1].Value = usedRange.Cells[i, j].Value;

          }
          dataGridView.Rows.Add(row);
      }

      workbook.Close();
      excelApp.Quit();

      System.Runtime.InteropServices.Marshal.ReleaseComObject(worksheet);
      System.Runtime.InteropServices.Marshal.ReleaseComObject(workbook);
      System.Runtime.InteropServices.Marshal.ReleaseComObject(excelApp);

      worksheet = null;
      workbook = null;
      excelApp = null;

      GC.Collect();
  }

DateGridView导出Excel文件

        /// <summary>
        /// Datagridview导出excel
        /// </summary>
        /// <param name="fileName"></param>
        /// <param name="myDGV"></param>
        private void DatagridViewToExcel( DataGridView myDGV)
        {
            string saveFileName = "";
            SaveFileDialog saveDialog = new SaveFileDialog();
            saveDialog.DefaultExt = "xls";
            saveDialog.Filter = "Excel文件|*.xls";
            if(saveDialog.ShowDialog()==DialogResult.Cancel)
            {
                return;
            }
            saveFileName = saveDialog.FileName;
            if (saveFileName.IndexOf(":") < 0) return; //被点了取消
            Microsoft.Office.Interop.Excel.Application xlApp = new Microsoft.Office.Interop.Excel.Application();
            if (xlApp == null)
            {
                MessageBox.Show("无法创建Excel对象，可能您的机子未安装Excel");
                return;
            }
            Microsoft.Office.Interop.Excel.Workbooks workbooks = xlApp.Workbooks;
            Microsoft.Office.Interop.Excel.Workbook workbook = workbooks.Add(Microsoft.Office.Interop.Excel.XlWBATemplate.xlWBATWorksheet);
            Microsoft.Office.Interop.Excel.Worksheet worksheet = (Microsoft.Office.Interop.Excel.Worksheet)workbook.Worksheets[1];//取得sheet1
                                                                                                                                  //写入标题
            for (int i = 0; i < myDGV.ColumnCount; i++)
            {

                worksheet.Cells[1, i + 1] = myDGV.Columns[i].HeaderText;
            }

            //写入数值
            for (int r = 0; r < myDGV.Rows.Count; r++)
            {
                for (int i = 0; i < myDGV.ColumnCount; i++)
                {
                    worksheet.Cells[r + 2, i + 1] = myDGV.Rows[r].Cells[i].Value;
                }
                System.Windows.Forms.Application.DoEvents();
            }
            worksheet.Columns.EntireColumn.AutoFit();//列宽自适应
            if (saveFileName != "")
            {
                try
                {
                    workbook.Saved = true;
                    workbook.SaveCopyAs(saveFileName);
                }
                catch (Exception ex)
                {
                    MessageBox.Show("导出文件时出错,文件可能正被打开！\n" + ex.Message);
                }
            }
            xlApp.Quit();
            GC.Collect();//强行销毁
            MessageBox.Show("文件： " + saveFileName + ".xls 保存成功", "信息提示",
            MessageBoxButtons.OK, MessageBoxIcon.Information);
        }

CSV与DatagridView之间操作

csv文件导入DateGridView

        /// <summary>
        /// 将csv文件数据导入datagridview
        /// </summary>
        /// <param name="csvPath"></param>
        /// <returns></returns>
        public static void ImportCSV(DataGridView dgv)
        {
            string filePath;
            OpenFileDialog openFileDialog = new OpenFileDialog();
            openFileDialog.Filter = "CSV files (*.csv)|*.csv";
            openFileDialog.FilterIndex = 0;
            if (openFileDialog.ShowDialog() == DialogResult.OK)
            {
                filePath = openFileDialog.FileName;
            }
            else
            {
                return;
            }
            System.Data.DataTable dt = new System.Data.DataTable();
            using (StreamReader sr = new StreamReader(filePath))
            {
                string[] headers = sr.ReadLine().Split(',');
                string headerValue = null;
                foreach (string header in headers)
                {
                    headerValue = header.Replace("\"", "");
                    dt.Columns.Add(headerValue);
                }
                while (!sr.EndOfStream)
                {
                    string[] rows = sr.ReadLine().Split(',');
                    DataRow dr = dt.NewRow();
                    for (int i = 0; i < headers.Length; i++)
                    {
                        dr[i] = rows[i].Replace("\"", "");
                    }
                    dt.Rows.Add(dr);
                }
            }
            dgv.DataSource = dt;
        }

DateGridView导出csv文件

       /// <summary>
       /// DateGridView导出到csv格式的Excel,通用  
       /// </summary>
       /// <param name="dgv"></param>
       public static void ExportToCSV(DataGridView dgv)
       {
           string filePath;
           SaveFileDialog saveFileDialog = new SaveFileDialog();
           saveFileDialog.Filter = "CSV files (*.csv)|*.csv";
           saveFileDialog.FilterIndex = 0;
           if (saveFileDialog.ShowDialog() == DialogResult.OK)
           {
               filePath = saveFileDialog.FileName;
           }
           else
           {
               return;
           }
           using (StreamWriter sw = new StreamWriter(filePath))
           {
               // 写入列标题
               string headers = string.Join(",", dgv.Columns.Cast<DataGridViewColumn>().Select(column => "\"" + column.HeaderText + "\"").ToArray());
               sw.WriteLine(headers);

               // 写入数据行
               foreach (DataGridViewRow row in dgv.Rows)
               {
                   string line = string.Join(",", row.Cells.Cast<DataGridViewCell>().Select(cell => "\"" + cell.Value?.ToString().Replace("\"", "\"\"") + "\"").ToArray());
                   sw.WriteLine(line);
               }
           }
       }

实例链接：https://download.csdn.net/download/lvxingzhe3/89977285

参考：

C# EXCEL创建，编辑，导出，按模板保存以及Excel与 DataGridView互转_c#创建excel文件-CSDN博客

C#NPOI应用（导入导出Excel）_c# npoi 操作excel-CSDN博客

使用 C# 和 OpenXML 读取大型 Excel 文件_openxml excel c#-CSDN博客