private void BTN_Export_Click(object sender, EventArgs e)
{
//Creating a file stream containing the Excel file to be opened
FileStream fstream = new FileStream(FOD_OpenFile.FileName, FileMode.Open);
//Instantiating a Workbook object
//Opening the Excel file through the file stream
Workbook workbook = new Workbook(fstream);
//Accessing the first worksheet in the Excel file
Worksheet worksheet = workbook.Worksheets[0];
//Exporting the contents of 2 rows and 2 columns starting from 1st cell to DataTable
DataTable dataTable = worksheet.Cells.ExportDataTable(0, 0,2, 2, true);
//Binding the DataTable with DataGrid
dataGridView1.DataSource = dataTable;
//Closing the file stream to free all resources
fstream.Close();
}