在excel/csv表中循環遍歷每個單元格

Question

此問題與我上一篇文章（link）有關。我想通過每個單元格，以便我可以清理我的非ascii值表（函數ReturnCleanASCII）正在用於此。但是，當我通過單元格時，我得到一個空值。

foreach (Excel.Range range in xlRange.Cells){ 
      Console.WriteLine(range.Value2.ToString()); 
} 

我使用上面的代碼要經過各單元代碼。這是一個不正確的方式來通過每個單元格？

using System; 
using System.Collections.Generic; 
using System.Linq; 
using System.Runtime.InteropServices; 
using System.Text; 
using System.Threading.Tasks; 
using Excel = Microsoft.Office.Interop.Excel; 

namespace ConsoleApplication1 
{ 
    class Program 
    { 
     static void Main(string[] args) 
     { 
      Excel.Application xlApp = new Excel.Application(); 
      Excel.Workbook xlWorkbook = xlApp.Workbooks.Open(@"C:\Users\username\Desktop\Error Records.csv"); 
      Excel.Worksheet xlWorksheet = xlWorkbook.Sheets[1]; 
      Excel.Range xlRange = xlWorksheet.UsedRange; 

      int lastUsedRow = xlWorksheet.Cells.Find("*", System.Reflection.Missing.Value, 
       System.Reflection.Missing.Value, System.Reflection.Missing.Value, 
       Excel.XlSearchOrder.xlByRows, Excel.XlSearchDirection.xlPrevious, 
       false, System.Reflection.Missing.Value, System.Reflection.Missing.Value).Row; 

      int lastUsedColumn = xlWorksheet.Cells.Find("*", System.Reflection.Missing.Value, 
       System.Reflection.Missing.Value, System.Reflection.Missing.Value, 
       Excel.XlSearchOrder.xlByColumns, Excel.XlSearchDirection.xlPrevious, 
       false, System.Reflection.Missing.Value, System.Reflection.Missing.Value).Column; 

      int lastColumnCount = lastUsedColumn; 



      for (int i = 1; i <= lastUsedColumn; i++) 
      { 
       for (int j = 1; j <= lastUsedRow; j++) 
       { 
        xlWorksheet.Cells[j, (lastColumnCount + 1)] = "Testing data 134"; 
       } 
      } 

      foreach (Excel.Range range in xlRange.Cells) 
      { 
       Console.WriteLine(range.Value2.ToString()); 
      } 


      xlWorksheet.Cells[1, (lastUsedColumn + 1)] = "Title"; 
      xlWorkbook.Save(); 
      //cleanup 
      GC.Collect(); 
      GC.WaitForPendingFinalizers(); 

      //rule of thumb for releasing com objects: 
      // never use two dots, all COM objects must be referenced and released individually 
      // ex: [somthing].[something].[something] is bad 

      //release com objects to fully kill excel process from running in the background 
      Marshal.ReleaseComObject(xlRange); 
      Marshal.ReleaseComObject(xlWorksheet); 

      //close and release 
      var data = ReturnCleanASCII(xlWorksheet.ToString()); 
      xlWorkbook.SaveAs("C:\\Users\\username\\Desktop\\Errors_four.csv".Trim(), Excel.XlFileFormat.xlCSV); 
      xlWorkbook.Close(); 
      Marshal.ReleaseComObject(xlWorkbook); 

      //quit and release 
      xlApp.Quit(); 
      Marshal.ReleaseComObject(xlApp); 

     } 

     public static string ReturnCleanASCII(string s) 
     { 
      StringBuilder sb = new StringBuilder(s.Length); 
      foreach (char c in s.ToCharArray()) 
      { 
       if ((int)c > 127) // you probably don't want 127 either 
        continue; 
       if ((int)c < 32) // I bet you don't want control characters 
        continue; 
       if (c == ',') 
        continue; 
       if (c == '"') 
        continue; 
       sb.Append(c); 
      } 
      return sb.ToString(); 
     } 
    } 
} 

錯誤：

Cannot perform runtime binding on a null reference

堆棧跟蹤：

at CallSite.Target(Closure , CallSite , Object) 
    at System.Dynamic.UpdateDelegates.UpdateAndExecute1[T0,TRet](CallSite site, T0 arg0) 
    at CallSite.Target(Closure , CallSite , Object) 
    at ConsoleApplication1.Program.Main(String[] args) in C:\Users\username\documents\visual studio 2015\Projects\ConsoleApplication1\ConsoleApplication1\Program.cs:line 44 
    at System.AppDomain._nExecuteAssembly(RuntimeAssembly assembly, String[] args) 
    at System.AppDomain.ExecuteAssembly(String assemblyFile, Evidence assemblySecurity, String[] args) 
    at Microsoft.VisualStudio.HostingProcess.HostProc.RunUsersAssembly() 
    at System.Threading.ThreadHelper.ThreadStart_Context(Object state) 
    at System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx) 
    at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx) 
    at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state) 
    at System.Threading.ThreadHelper.ThreadStart() 

Answer 1

使用Convert.ToString(range.Value2)而不是range.Value2.ToString()

參見：Cannot perform runtime binding on a null reference - Empty Excel Cells