Question

was experimenting with reading from an excel workbook and noticed it takes a long time to read a sheet with 3560 rows and 7 columns, about 1 minute and 17 seconds. All I did was loop through the whole sheet and store the values in a list.

Is this normal, or am I doing something wrong ?

 static void Main(string[] args)
    {
        List<string> testList = new List<string>();
        Excel.Application excelApp = new Excel.Application();
        Excel.Workbook workbook = excelApp.Workbooks.Open(@"C:\Users\rnewell\Desktop\FxData.xlsx");
        Excel.Worksheet worksheet = workbook.Sheets[1];
        Excel.Range range = worksheet.UsedRange;

        int rowCount = range.Rows.Count;
        int colCount = range.Columns.Count;



        int rowCounter = 1;
        int colCounter = 1;

        while (rowCounter < rowCount)
        {
            colCounter = 1;
            while (colCounter <= colCount)
            {
                //Console.Write(range.Cells[rowCounter, colCounter].Value2.ToString() + " ");
                testList.Add(range.Cells[rowCounter, colCounter].Value2.ToString());
                colCounter++;
            }
            Console.WriteLine();
            rowCounter++;


        }



        Console.ReadKey();
        excelApp.Workbooks.Close();


    }

Answer 1

Since you are loading data from the Open XML (*.xlsx) file format, I would suggest you use Open XML SDK. It doesn’t start Excel in the background which is always a good thing, in particular if you need to run your code non-interactively.

I’ve also written a blog post on different methods of accessing data in Excel which you might find useful.