我們如何讀取Excel中特定行或列的數據？

Question

這是我正在使用的代碼，但它讀取整個Excel工作表。我怎樣才能從一個特定的列或行讀取數據？

Application xlApp; 
Workbook xlWorkBook; 
Worksheet xlWorkSheet; 
Range range; 

string str; 
int rCnt = 0; 
int cCnt = 0; 

xlApp = new Application(); 
xlWorkBook = xlApp.Workbooks.Open("c:\\telltales.xlsx"); 
xlWorkSheet = (Worksheet)xlWorkBook.Worksheets.get_Item(1); 

range = xlWorkSheet.UsedRange; 

for (rCnt = 1; rCnt <= range.Rows.Count; rCnt++) 
{ 
    for (cCnt = 1; cCnt <= range.Columns.Count; cCnt++) 
    { 
      str = (string)(range.Cells[rCnt, cCnt] as Range).Value2; 
      Console.WriteLine(str); 
    } 
} 

Answer 1

對於簡單讀取一個單元格或一系列單元格，請考慮使用OleDb數據提供程序，如下所示。使用OleDb，不需要擔心清理對象，並且如果程序意外終止，辦公自動化對象與OleDb不同，將留在內存中。下面我介紹了一種體面的方法來構建連接字符串。歡迎來自OneDrive的download the project。現在

using System; 
using System.Data; 
using System.Data.OleDb; 

namespace ExcelReadRangeSimple 
{ 
    internal class Program 
    { 
     /// <summary> 
     /// This functiuon is an example of how you can setup a connection for an 
     /// Excel file based on the extension. 
     /// </summary> 
     /// <param name="FileName"></param> 
     /// <param name="Header"></param> 
     /// <returns></returns> 
     /// <remarks> 
     /// There are no guaranty that the settings below will be correct for 
     /// your Excel file. Things to tweak if it does not work 
     /// 
     /// - IMEX 
     /// - HDR 
     /// 
     /// SeeAlso for IMEX 
     /// http://www.codeproject.com/Articles/37055/Working-with-MS-Excel-xls-xlsx-Using-MDAC-and-Oled 
     /// </remarks> 
     static public string ConnectionString(string FileName, string Header) 
     { 
      OleDbConnectionStringBuilder Builder = new OleDbConnectionStringBuilder(); 
      if (System.IO.Path.GetExtension(FileName).ToUpper() == ".XLS") 
      { 
       Builder.Provider = "Microsoft.Jet.OLEDB.4.0"; 
       Builder.Add("Extended Properties", string.Format("Excel 8.0;IMEX=1;HDR={0};", Header)); 
      } 
      else 
      { 
       Builder.Provider = "Microsoft.ACE.OLEDB.12.0"; 
       Builder.Add("Extended Properties", string.Format("Excel 12.0;IMEX=1;HDR={0};", Header)); 
      } 

      Builder.DataSource = FileName; 

      return Builder.ConnectionString; 
     } 

     /// <summary> 
     /// 
     /// </summary> 
     /// <param name="FileName">Full path and file name to read</param> 
     /// <param name="SheetName">Name of sheet to read, do not append $</param> 
     /// <param name="StartCell">Cell to start range i.e. A1</param> 
     /// <param name="EndCell">Cell to end range i.e. D30</param> 
     static private void DemoReadData(string FileName, string SheetName, string StartCell, string EndCell) 
     { 
      System.Text.StringBuilder sb = new System.Text.StringBuilder(); 
      DataTable dt = new DataTable(); 

      using (OleDbConnection cn = new OleDbConnection { ConnectionString = ConnectionString(FileName, "No") }) 
      { 
       cn.Open(); 

       string SelectStatement = string.Format("SELECT F1 As Company, F2 As Contact FROM [{0}${1}:{2}]", SheetName, StartCell, EndCell); 

       using (OleDbCommand cmd = new OleDbCommand { CommandText = SelectStatement, Connection = cn }) 
       { 

        Console.WriteLine(); 
        Console.WriteLine("Connection string is"); 
        Console.WriteLine(cn.ConnectionString); 
        Console.WriteLine(); 
        Console.WriteLine(); 

        OleDbDataReader dr = cmd.ExecuteReader(); 
        if (dr.HasRows) 
        { 
         while (dr.Read()) 
         { 
          Console.WriteLine(" {0,-25} {1}", dr.GetString(1), dr.GetString(0)); 
         } 
        } 
        else 
        { 
         Console.WriteLine("No rows!!!"); 
        } 
       } 
      } 



     } 
     private static void Main(string[] args) 
     { 
      string FileName = System.IO.Path.Combine(AppDomain.CurrentDomain.BaseDirectory, "WS1.xlsx"); 

      DemoReadData(FileName, "Sheet4", "C7", "D16"); 
      Console.ReadLine(); 
     } 
    } 
} 

，如果你真的想使用辦公自動化考慮下面介紹該模型下面是細緻與對象如何使用，並銷燬，以確保使用的是正確清理所有對象。很多時候開發者都沒有花時間去做這件事，而應該這樣做。

public void OpenExcel(string FileName, string SheetName, string CellAddress, string CellValue) 
{ 
    List<string> SheetNames = new List<string>(); 

    bool Proceed = false; 
    Excel.Application xlApp = null; 
    Excel.Workbooks xlWorkBooks = null; 
    Excel.Workbook xlWorkBook = null; 
    Excel.Worksheet xlWorkSheet = null; 
    Excel.Sheets xlWorkSheets = null; 

    xlApp = new Excel.Application(); 
    xlApp.DisplayAlerts = false; 
    xlWorkBooks = xlApp.Workbooks; 
    xlWorkBook = xlWorkBooks.Open(FileName); 

    xlApp.Visible = false; 
    xlWorkSheets = xlWorkBook.Sheets; 

    for (int x = 1; x <= xlWorkSheets.Count; x++) 
    { 
     xlWorkSheet = (Excel.Worksheet)xlWorkSheets[x]; 

     SheetNames.Add(xlWorkSheet.Name); 

     if (xlWorkSheet.Name == SheetName) 
     { 
      Proceed = true; 
      Excel.Range xlRange1 = null; 
      xlRange1 = xlWorkSheet.Range[CellAddress]; 
      xlRange1.Value = CellValue; 

      string value = xlRange1.Value; 
      Console.WriteLine(value); 

      Marshal.FinalReleaseComObject(xlRange1); 
      xlRange1 = null; 
      xlWorkSheet.SaveAs(FileName); 
      break; 
     } 

     System.Runtime.InteropServices.Marshal.FinalReleaseComObject(xlWorkSheet); 
     xlWorkSheet = null; 
    } 

    xlWorkBook.Close(); 
    xlApp.Quit(); 

    ReleaseComObject(xlWorkSheets); 
    ReleaseComObject(xlWorkSheet); 
    ReleaseComObject(xlWorkBook); 
    ReleaseComObject(xlWorkBooks); 
    ReleaseComObject(xlApp); 

    if (Proceed) 
    { 
     MessageBox.Show("Found sheet, do your work here."); 
    } 
    else 
    { 
     MessageBox.Show("Sheet not located"); 
    } 

    MessageBox.Show("Sheets available \n" + String.Join("\n", SheetNames.ToArray())); 
} 

private void ReleaseComObject(object obj) 
{ 
    try 
    { 
     System.Runtime.InteropServices.Marshal.ReleaseComObject(obj); 
     obj = null; 
    } 
    catch (Exception) 
    { 
     obj = null; 
    } 
} 

public string GetCellValue(string FileName, string SheetName, string CellAddress) 
{ 
    string CellValue = ""; 

    Excel.Application xlApp = null; 
    Excel.Workbooks xlWorkBooks = null; 
    Excel.Workbook xlWorkBook = null; 
    Excel.Worksheet xlWorkSheet = null; 
    Excel.Sheets xlWorkSheets = null; 

    xlApp = new Excel.Application(); 
    xlApp.DisplayAlerts = false; 
    xlWorkBooks = xlApp.Workbooks; 
    xlWorkBook = xlWorkBooks.Open(FileName); 

    xlApp.Visible = false; 
    xlWorkSheets = xlWorkBook.Sheets; 

    for (int x = 1; x <= xlWorkSheets.Count; x++) 
    { 
     xlWorkSheet = (Excel.Worksheet)xlWorkSheets[x]; 

     if (xlWorkSheet.Name == SheetName) 
     { 
      Excel.Range xlRange1 = null; 
      xlRange1 = xlWorkSheet.Range[CellAddress]; 
      CellValue = xlRange1.Value; 
      Marshal.FinalReleaseComObject(xlRange1); 
      xlRange1 = null; 
      xlWorkSheet.SaveAs(FileName); 
      break; 
     } 

     System.Runtime.InteropServices.Marshal.FinalReleaseComObject(xlWorkSheet); 
     xlWorkSheet = null; 
    } 

    xlWorkBook.Close(); 
    xlApp.Quit(); 

    ReleaseComObject(xlWorkSheets); 
    ReleaseComObject(xlWorkSheet); 
    ReleaseComObject(xlWorkBook); 
    ReleaseComObject(xlWorkBooks); 
    ReleaseComObject(xlApp); 
    return CellValue; 
}