从 FlowDocument 创建 XPS 文档并即时附加它

我有一个 FlowDocument，我想将其转换为 XPS 文档并将其附加到电子邮件中并一起发送。我正在使用这个代码

public static Stream FlowDocumentToXPS(FlowDocument flowDocument, int width, int height)
{
    MemoryStream stream = new MemoryStream();
    using (Package package = Package.Open(stream, FileMode.Create,FileAccess.ReadWrite))
    {         
        using (XpsDocument xpsDoc = new XpsDocument(package, CompressionOption.Maximum))
        {
            xpsDoc.AddFixedDocumentSequence();
            XpsSerializationManager rsm = new XpsSerializationManager(new XpsPackagingPolicy(xpsDoc), false);
         
            DocumentPaginator paginator = ((IDocumentPaginatorSource)flowDocument).DocumentPaginator;
            paginator.PageSize = new System.Windows.Size(width, height);              
            rsm.SaveAsXaml(paginator);                  
            rsm.Commit();
        }

        return stream;
    }
}

然后我使用以下代码附加它：

Attachment xps = new Attachment(FlowDocumentToXPS(FD, 768, 676), "FileName.xps", "application/vnd.ms-xpsdocument");

其中 FD 是我要转换的 FlowDocument，我收到附加的 0.0KB 大小的 XPS 文件，但无法使用 XPS 查看器打开它，我在这里缺少什么？

解决了，这是最终有效的代码：

    public static MemoryStream FlowDocumentToXPS(FlowDocument flowDocument, int width, int height)
    {
        MemoryStream stream = new MemoryStream();
        using (Package package = Package.Open(stream, FileMode.Create, FileAccess.ReadWrite))
        {
            using (XpsDocument xpsDoc = new XpsDocument(package, CompressionOption.Maximum))
            {                  
                XpsSerializationManager rsm = new XpsSerializationManager(new XpsPackagingPolicy(xpsDoc), false);
                DocumentPaginator paginator = ((IDocumentPaginatorSource)flowDocument).DocumentPaginator;
                paginator.PageSize = new System.Windows.Size(width, height);
                rsm.SaveAsXaml(paginator);
                rsm.Commit();                
            }
        }
        stream.Position = 0;
        Console.WriteLine(stream.Length);
        Console.WriteLine(stream.Position);
        return stream;   
    }

然后我使用以下代码附加它：

Attachment xps = new Attachment(FlowDocumentToXPS(FD, 768, 676), "FileName.xps", "application/vnd.ms-xpsdocument");

其中 FD 是我要转换的 FlowDocument。