using System.IO;
public void ExportExcel2(DataTable dt, string fileName) 
{ string FileName = fileName; 
  FileStream objFileStream; 
 StreamWriter objStreamWriter; 
 string strLine = ""; 
 objFileStream = new FileStream(FileName, FileMode.OpenOrCreate, FileAccess.Write); objStreamWriter = new StreamWriter(objFileStream, System.Text.Encoding.Unicode);
  for (int i = 0; i < dt.Columns.Count; i++) 
  { 
   strLine = strLine + dt.Columns[i].ColumnName.ToString() + Convert.ToChar(9);
   } 
   
  objStreamWriter.WriteLine(strLine); 
  strLine = "";
   for (int i = 0; i < dt.Rows.Count; i++)
  { 
     for (int j = 0; j < dt.Columns.Count; j++) 
     { 
          strLine = strLine + dt.Rows[i][j].ToString() + Convert.ToChar(9); 
      }  
     objStreamWriter.WriteLine(strLine); strLine = ""; 
   } 
   objStreamWriter.Close(); 
   objFileStream.Close();
 }

------解决方案--------------------
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