Overloads Function Open( _
   ByVal filename As String _
) As IWorkbook

IWorkbook Open( 
   string filename
)

class Program
{
    static void Main()
    {
        // Create a new empty workbook set.
        SpreadsheetGear.IWorkbookSet workbookSet = SpreadsheetGear.Factory.GetWorkbookSet();
        // Create a new empty workbook in the workbook set.
        SpreadsheetGear.IWorkbook workbook = workbookSet.Workbooks.Add();
        // Save to C:\MyData.xls.
        workbook.SaveAs("C:\\MyData.xls", SpreadsheetGear.FileFormat.XLS97);
        // Set Sheet1!A1 to "Hello World!".
        workbook.Worksheets["Sheet1"].Cells["A1"].Value = "Hello World!";
        // Save to C:\MyData.xls again.
        workbook.Save();
        // Close the workbook, removing it from the workbook set.
        workbookSet.Workbooks.Close();
        // Open the saved workbook from memory.
        workbook = workbookSet.Workbooks.Open("C:\\MyData.xls");
        // Output Sheet1!A1.
        System.Console.WriteLine(workbook.Worksheets["Sheet1"].Cells["A1"].Value.ToString());
    }
}

Class Program
    Shared Sub Main()
        ' Create a new empty workbook set.
        Dim workbookSet As SpreadsheetGear.IWorkbookSet = SpreadsheetGear.Factory.GetWorkbookSet()
        ' Create a new empty workbook in the workbook set.
        Dim workbook As SpreadsheetGear.IWorkbook = workbookSet.Workbooks.Add()
        ' Save to C:\MyData.xls as an Excel file.
        workbook.SaveAs("C:\\MyData.xls", SpreadsheetGear.FileFormat.XLS97)
        ' Set Sheet1!A1 to "Hello World!".
        workbook.Worksheets("Sheet1").Cells("A1").Value = "Hello World!"
        ' Save to C:\MyData.xls again.
        workbook.Save()
        ' Close the workbook, removing it from the workbook set.
        workbookSet.Workbooks.Close()
        ' Open the saved workbook from memory.
        workbook = workbookSet.Workbooks.Open("C:\\MyData.xls")
        ' Output Sheet1!A1.
        System.Console.WriteLine(workbook.Worksheets("Sheet1").Cells("A1").Value.ToString())
    End Sub 'Main
End Class 'Program