I have created a class for reading data from an Excel sheet and holding on the variable.  I am not sure if my code is optimized, meaning I will be reading heavily from Excel.Is there a room to further optimized this code?  I will be using this class heaving in my code, and I wanted to get some opinions/feedback.I will be calling something like this:ExcelReader xl = new ExcelReader();string sss = xl.ExcelOpenSpreadsheets(mysheet);//etc...public class ExcelReader  {                 Application _excelApp;    public ExcelReader()    {        _excelApp = new Application();    }    public string ExcelOpenSpreadsheets(string sheetName)    {        string _txt = string.Empty;        try        {            Workbook workBook = _excelApp.Workbooks.Open(filename_here,....);            _txt = ExcelScanIntenal(workBook, sheetName);        }        catch        {            //            // Deal with exceptions.            //        }        return _txt;    }    private string ExcelScanIntenal(Workbook workBookIn, string sheetName)    {        Worksheet sheet = workBookIn.Sheets[sheetName] as Worksheet;        Range a1 = sheet.get_Range(A1, B2);        if (a1 != null)        {            string formattedText = r.Text;                           }        return formattedText;     }
Reading from an Excel sheet
c#;optimization;excel