經常會遇見把excel資料讀出來，轉變成自己需要的格式，程式碼如下：

  static void ChangeFileFormat(string strExcelPath, string newFileName, int rowOff=0,params int[] arrRmColumn)
        {
            DataTable dataTable = GetExcelTableByOleDB(strExcelPath);

            StringBuilder strContent = new StringBuilder();
            for
 
 (int i = rowOff; i < dataTable.Rows.Count; i++)
            {
                Object[] arrItem = dataTable.Rows[i].ItemArray;
                string rowData = string.Empty;
                for (int column = 0; column < arrItem.Length; column++)
                {
                    bool bAddColumn = true
 
;
                    if (arrRmColumn != null)
                    {
                        for (int rmcolumnIndex = 0; rmcolumnIndex < arrRmColumn.Length; ++rmcolumnIndex)
                        {
                            if (arrRmColumn[rmcolumnIndex] == column)
                            {
                                bAddColumn = false
 
;
                                break;
                            }
                        }
                    }
                    if (bAddColumn)
                    {
                        rowData += (arrItem[column] + ">");
                    }
                }
                strContent.Append(rowData + "\n");
            }

            string strTargetFilePath = System.Environment.CurrentDirectory + "\\TargetFile\\" + newFileName;

            if (File.Exists(strTargetFilePath))
            {
                File.Delete(strTargetFilePath);
            }

            using (StreamWriter write = new StreamWriter(strTargetFilePath))
            {
                write.Write(strContent.ToString());
                write.Flush();
            }

            Console.WriteLine("change successfully!");
        }

        public static DataTable GetExcelTableByOleDB(string strExcelPath)
        {
            try
            {
                DataTable dtExcel = new DataTable();
                //資料表
                DataSet ds = new DataSet();
                //獲取副檔名
                string strExtension = System.IO.Path.GetExtension(strExcelPath);
                string strFileName = System.IO.Path.GetFileName(strExcelPath);
                //Excel的連線
                OleDbConnection objConn = null;
                switch (strExtension)
                {
                case ".xls":
                     objConn = new OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + strExcelPath + ";" + "Extended Properties=\"Excel 8.0;HDR=NO;IMEX=1;\"");
                     break;
                case ".xlsx":
                     objConn = new OleDbConnection("Provider=Microsoft.ACE.OLEDB.12.0;Data Source=" + strExcelPath + ";" + "Extended Properties=\"Excel 12.0;HDR=NO;IMEX=1;\"");
                     break;
                default:
                     objConn = null;
                     break;
                 }
                if (objConn == null)
                {
                    return null;
                }
                objConn.Open();


               //獲取Excel中所有Sheet表的資訊
               DataTable schemaTable = objConn.GetOleDbSchemaTable(OleDbSchemaGuid.Tables, null);
               //獲取Excel的第一個Sheet表名
               string tableName = schemaTable.Rows[0][2].ToString().Trim();

               string strSql = "select * from [" + tableName + "]";

               //獲取Excel指定Sheet表中的資訊
               //OleDbCommand objCmd = new OleDbCommand(strSql, objConn);
               OleDbDataAdapter myData = new OleDbDataAdapter(strSql, objConn);
               myData.Fill(ds, tableName);//填充資料

               objConn.Close();

               //dtExcel即為excel檔案中指定表中儲存的資訊
               dtExcel = ds.Tables[tableName];
               return dtExcel;
           }
           catch
           {
               return null;
           }
        }