Öffnen eines Kalkulationstabellendokument aus einem Stream

// Add a new worksheet.
WorksheetPart newWorksheetPart = workbookPart.AddNewPart<WorksheetPart>();
newWorksheetPart.Worksheet = new Worksheet(new SheetData());

' Add a new worksheet.
Dim newWorksheetPart As WorksheetPart = workbookPart.AddNewPart(Of WorksheetPart)()
newWorksheetPart.Worksheet = New Worksheet(New SheetData())

using (FileStream fileStream = new FileStream(args[0], FileMode.Open, FileAccess.ReadWrite))
{
    OpenAndAddToSpreadsheetStream(fileStream);
}

Using fileStream As New FileStream(args(0), FileMode.Open, FileAccess.ReadWrite)
    OpenAndAddToSpreadsheetStream(fileStream)
End Using

static void OpenAndAddToSpreadsheetStream(Stream stream)
{
    // Open a SpreadsheetDocument based on a stream.
    using (SpreadsheetDocument spreadsheetDocument = SpreadsheetDocument.Open(stream, true))
    {

        if (spreadsheetDocument is not null)
        {
            // Get or create the WorkbookPart
            WorkbookPart workbookPart = spreadsheetDocument.WorkbookPart ?? spreadsheetDocument.AddWorkbookPart();


            // Add a new worksheet.
            WorksheetPart newWorksheetPart = workbookPart.AddNewPart<WorksheetPart>();
            newWorksheetPart.Worksheet = new Worksheet(new SheetData());


            Workbook workbook = workbookPart.Workbook ?? new Workbook();

            if (workbookPart.Workbook is null)
            {
                workbookPart.Workbook = workbook;
            }

            Sheets sheets = workbook.GetFirstChild<Sheets>() ?? workbook.AppendChild(new Sheets());
            string relationshipId = workbookPart.GetIdOfPart(newWorksheetPart);

            // Get a unique ID for the new worksheet.
            uint sheetId = 1;

            if (sheets.Elements<Sheet>().Count() > 0)
            {
                sheetId = (sheets.Elements<Sheet>().Select(s => s.SheetId?.Value).Max() + 1) ?? (uint)sheets.Elements<Sheet>().Count() + 1;
            }

            // Give the new worksheet a name.
            string sheetName = "Sheet" + sheetId;

            // Append the new worksheet and associate it with the workbook.
            Sheet sheet = new Sheet() { Id = relationshipId, SheetId = sheetId, Name = sheetName };
            sheets.Append(sheet);
        }
    }
}

Sub OpenAndAddToSpreadsheetStream(stream As Stream)
    ' Open a SpreadsheetDocument based on a stream.
    Using spreadsheetDocument As SpreadsheetDocument = SpreadsheetDocument.Open(stream, True)

        If spreadsheetDocument IsNot Nothing Then
            ' Get or create the WorkbookPart
            Dim workbookPart As WorkbookPart = If(spreadsheetDocument.WorkbookPart, spreadsheetDocument.AddWorkbookPart())


            ' Add a new worksheet.
            Dim newWorksheetPart As WorksheetPart = workbookPart.AddNewPart(Of WorksheetPart)()
            newWorksheetPart.Worksheet = New Worksheet(New SheetData())


            Dim workbook As Workbook = If(workbookPart.Workbook, New Workbook())

            If workbookPart.Workbook Is Nothing Then
                workbookPart.Workbook = workbook
            End If

            Dim sheets As Sheets = If(workbook.GetFirstChild(Of Sheets)(), workbook.AppendChild(New Sheets()))
            Dim relationshipId As String = workbookPart.GetIdOfPart(newWorksheetPart)

            ' Get a unique ID for the new worksheet.
            Dim sheetId As UInteger = 1

            If sheets.Elements(Of Sheet)().Count() > 0 Then
                sheetId = sheets.Elements(Of Sheet)().Select(Function(s) s.SheetId?.Value).Max() + 1
            End If

            ' Give the new worksheet a name.
            Dim sheetName As String = "Sheet" & sheetId

            ' Append the new worksheet and associate it with the workbook.
            Dim sheet As New Sheet() With {
                .Id = relationshipId,
                .SheetId = sheetId,
                .Name = sheetName
            }
            sheets.Append(sheet)
        End If
    End Using
End Sub