After AddWorkbookPart() I recieved "Cannot retrieve parts of writeonly container" Exception from System.IO.Packaging

[Reules]

Describe the bug
Recently I updated OpenXML from 2.18.0 to 3.1.0.
The function AddWorkbookPart() didn't work anymore.
Always get the System.IO.IOException "Cannot retrieve parts of writeonly container".

Screenshots

Anyone knows the problem?

[mikeebowen]

Hi @Reules, can you share the code that causes this error?

Thanks!

[mikeebowen]

Hi @Reules,

I am using v3.1.1 and the following code with AddWorkbookPart creates an xlsx with no errors. If this doesn't help with your issue, please share your repro code.

using DocumentFormat.OpenXml;
using DocumentFormat.OpenXml.Packaging;
using DocumentFormat.OpenXml.Spreadsheet;

string xlsx = @"C:\some\dir\AddWorkbookPart.xlsx";

// Create a workbook document by supplying the file path.
// By default, AutoSave = true, Editable = true, and Type = xlsx.
using (var spreadsheetDocument = SpreadsheetDocument.Create(xlsx, SpreadsheetDocumentType.Workbook))
{
    // Add a WorkbookPart to the document.
    WorkbookPart workbookPart = spreadsheetDocument.AddWorkbookPart();
    workbookPart.Workbook = new Workbook();

    // Add a WorksheetPart to the WorkbookPart.
    WorksheetPart worksheetPart = workbookPart.AddNewPart<WorksheetPart>();
    worksheetPart.Worksheet = new Worksheet(new SheetData());

    // Add Sheets to the workbook.
    Sheets sheets = workbookPart.Workbook.AppendChild(new Sheets());

    // Append a new worksheet and associate it with the workbook.
    Sheet sheet = new Sheet()
    {
        Id = spreadsheetDocument?.WorkbookPart?.GetIdOfPart(worksheetPart),
        SheetId = 1,
        Name = "MyNewSheet"
    };

    sheets.Append(sheet);
}

[mikeebowen]

Hi @Reules, Are you somehow opening the file as write only?

[Reules]

Hi @mikeebowen Thanks for the reply, yes, before the AddWorkbookPart, i used
var package = Package.Open(fs, FileMode.Create, FileAccess.Write), which did't cause any problem with Openxml 2.18.0
Maybe this was fixed in Openxml 3.1.0
Thank you for your help

[mikeebowen]

In System.IO.Packaging.Package, the GetRelationshipsHelper method calls a method ThrowIfWriteOnly, which throws IOException(System.SR.CannotRetrievePartsOfWriteOnlyContainer) if it is write only. The git commit for this is from 9 years ago, so I don't know how it works in 2.18.0, but it shouldn't. View it on GitHub here: GetRelationshipsHelper method.

Since what you're seeing is the expected behavior, I will close this as by design.