OpenFileDialog openFileDialog = new OpenFileDialog();
openFileDialog.Filter = "Excel File (.xlsx)|*.xlsx";
bool? useClick = openFileDialog.ShowDialog();
if (useClick == true)
{
var stream = openFileDialog.File.OpenRead();
stream.Seek(0, System.IO.SeekOrigin.Begin);
gcSpreadSheet1.OpenExcel(stream);
//gcSpreadSheet1.OpenExcel(stream, GrapeCity.Windows.SpreadSheet.Data.ExcelOpenFlags.DataOnly);
//gcSpreadSheet1.OpenExcel(stream, GrapeCity.Windows.SpreadSheet.Data.ExcelOpenFlags.DataOnly, "12Test9");
//gcSpreadSheet1.OpenExcel(stream, "12Test9");
stream.Dispose();
}