Try to open my Excel file using C# and get an error

Question

I try to read my Exel file from code and received System.InvalidCastException:

Additional information: Unable to cast COM object of type \'System.__Co

Answer 1

Try the below code and see if it works, if not let us know what problems you have:

using Excel = Microsoft.Office.Interop.Excel;

namespace Excel_Sample
{
    public partial class YourClass
    {
        Excel.Application appExcel;
        Excel.Workbook newWorkbook;
        Excel.Worksheet objsheet;
        string file = @"D:\file.xlsx";

        static void excel_init()
        {
            if (System.IO.File.Exists(file))
            {
                //Start Excel and get Application object.
                appExcel = new Excel.Application();
                //Get a workbook.;
                newWorkbook = (Excel.Workbook)(appExcel.Workbooks.Open(file));

                int count = newWorkbook.Worksheets.Count;
                if (count > 0)
                {
                    //Get Your Worksheet
                    objsheet = (Excel.Worksheet)newWorkbook.ActiveSheet;
                }
            }
            else
            {
                MessageBox.Show("Unable to open file!");
                System.Runtime.InteropServices.Marshal.ReleaseComObject(appExcel);
                appExcel = null;
                System.Windows.Forms.Application.Exit();
            }
        }
    }
}