異なる方向が混在するPDF、すべてのページが横向きに印刷される

using IronPrint;
using IronPdf;
await PrintDocumentByOrientationBatchesAsync(
    documentPath: documentPath,
    printerName: printerName,
    numberOfCopies: effectiveCopies);
async Task PrintDocumentByOrientationBatchesAsync(
    string documentPath,
    string printerName,
    int numberOfCopies)
{
    var tempFolder = Path.Combine(
        Path.GetTempPath(),
        "ironprint-orientation-workaround",
        Guid.NewGuid().ToString("N"));
    Directory.CreateDirectory(tempFolder);
    try
    {
        using var pdf = PdfDocument.FromFile(documentPath);
        var batches = GetConsecutiveOrientationBatches(pdf);
        // Since the document is printed in multiple jobs, copies are handled manually
        // to preserve the full document order per copy.
        for (var copy = 1; copy <= numberOfCopies; copy++)
        {
            foreach (var batch in batches)
            {
                var batchPath = Path.Combine(
                    tempFolder,
                    $"copy_{copy}_pages_{batch.StartPageNumber}_{batch.EndPageNumber}_{batch.Orientation}.pdf");
                using var batchPdf = pdf.CopyPages(batch.StartIndex, batch.EndIndex);
                batchPdf.SaveAs(batchPath);
                var printSettings = new PrintSettings
                {
                    PrinterName = printerName,
                    NumberOfCopies = 1,
                    PaperOrientation = batch.Orientation == DetectedPageOrientation.Landscape
                        ? PaperOrientation.Landscape
                        : PaperOrientation.Portrait,
                    PaperSize = PaperSize.PrinterDefault
                };
                await Printer.PrintAsync(batchPath, printSettings);
                // Optional delay to help ensure print jobs are queued in order.
                await Task.Delay(500);
            }
        }
    }
    finally
    {
        try
        {
            Directory.Delete(tempFolder, recursive: true);
        }
        catch
        {
            // Ignore cleanup errors in case the print spooler is still accessing the files.
        }
    }
}
List<PageOrientationBatch> GetConsecutiveOrientationBatches(PdfDocument pdf)
{
    var batches = new List<PageOrientationBatch>();
    if (pdf.PageCount == 0)
    {
        return batches;
    }
    var currentOrientation = GetPageOrientation(pdf.Pages[0].Width, pdf.Pages[0].Height);
    var batchStartIndex = 0;
    for (var pageIndex = 1; pageIndex < pdf.PageCount; pageIndex++)
    {
        var page = pdf.Pages[pageIndex];
        var pageOrientation = GetPageOrientation(page.Width, page.Height);
        if (pageOrientation != currentOrientation)
        {
            batches.Add(new PageOrientationBatch(
                StartIndex: batchStartIndex,
                EndIndex: pageIndex - 1,
                Orientation: currentOrientation));
            batchStartIndex = pageIndex;
            currentOrientation = pageOrientation;
        }
    }
    batches.Add(new PageOrientationBatch(
        StartIndex: batchStartIndex,
        EndIndex: pdf.PageCount - 1,
        Orientation: currentOrientation));
    return batches;
}
DetectedPageOrientation GetPageOrientation(double width, double height)
{
    return width > height
        ? DetectedPageOrientation.Landscape
        : DetectedPageOrientation.Portrait;
}
record PageOrientationBatch(
    int StartIndex,
    int EndIndex,
    DetectedPageOrientation Orientation)
{
    public int StartPageNumber => StartIndex + 1;
    public int EndPageNumber => EndIndex + 1;
}
enum DetectedPageOrientation
{
    Portrait,
    Landscape
}

Imports IronPrint
Imports IronPdf
Imports System.IO

Await PrintDocumentByOrientationBatchesAsync(documentPath:=documentPath, printerName:=printerName, numberOfCopies:=effectiveCopies)

Private Async Function PrintDocumentByOrientationBatchesAsync(documentPath As String, printerName As String, numberOfCopies As Integer) As Task
    Dim tempFolder = Path.Combine(Path.GetTempPath(), "ironprint-orientation-workaround", Guid.NewGuid().ToString("N"))
    Directory.CreateDirectory(tempFolder)
    Try
        Using pdf = PdfDocument.FromFile(documentPath)
            Dim batches = GetConsecutiveOrientationBatches(pdf)
            ' Since the document is printed in multiple jobs, copies are handled manually
            ' to preserve the full document order per copy.
            For copy = 1 To numberOfCopies
                For Each batch In batches
                    Dim batchPath = Path.Combine(tempFolder, $"copy_{copy}_pages_{batch.StartPageNumber}_{batch.EndPageNumber}_{batch.Orientation}.pdf")
                    Using batchPdf = pdf.CopyPages(batch.StartIndex, batch.EndIndex)
                        batchPdf.SaveAs(batchPath)
                        Dim printSettings = New PrintSettings With {
                            .PrinterName = printerName,
                            .NumberOfCopies = 1,
                            .PaperOrientation = If(batch.Orientation = DetectedPageOrientation.Landscape, PaperOrientation.Landscape, PaperOrientation.Portrait),
                            .PaperSize = PaperSize.PrinterDefault
                        }
                        Await Printer.PrintAsync(batchPath, printSettings)
                        ' Optional delay to help ensure print jobs are queued in order.
                        Await Task.Delay(500)
                    End Using
                Next
            Next
        End Using
    Finally
        Try
            Directory.Delete(tempFolder, recursive:=True)
        Catch
            ' Ignore cleanup errors in case the print spooler is still accessing the files.
        End Try
    End Try
End Function

Private Function GetConsecutiveOrientationBatches(pdf As PdfDocument) As List(Of PageOrientationBatch)
    Dim batches = New List(Of PageOrientationBatch)()
    If pdf.PageCount = 0 Then
        Return batches
    End If
    Dim currentOrientation = GetPageOrientation(pdf.Pages(0).Width, pdf.Pages(0).Height)
    Dim batchStartIndex = 0
    For pageIndex = 1 To pdf.PageCount - 1
        Dim page = pdf.Pages(pageIndex)
        Dim pageOrientation = GetPageOrientation(page.Width, page.Height)
        If pageOrientation <> currentOrientation Then
            batches.Add(New PageOrientationBatch(StartIndex:=batchStartIndex, EndIndex:=pageIndex - 1, Orientation:=currentOrientation))
            batchStartIndex = pageIndex
            currentOrientation = pageOrientation
        End If
    Next
    batches.Add(New PageOrientationBatch(StartIndex:=batchStartIndex, EndIndex:=pdf.PageCount - 1, Orientation:=currentOrientation))
    Return batches
End Function

Private Function GetPageOrientation(width As Double, height As Double) As DetectedPageOrientation
    Return If(width > height, DetectedPageOrientation.Landscape, DetectedPageOrientation.Portrait)
End Function

Private NotInheritable Class PageOrientationBatch
    Public Property StartIndex As Integer
    Public Property EndIndex As Integer
    Public Property Orientation As DetectedPageOrientation

    Public Sub New(StartIndex As Integer, EndIndex As Integer, Orientation As DetectedPageOrientation)
        Me.StartIndex = StartIndex
        Me.EndIndex = EndIndex
        Me.Orientation = Orientation
    End Sub

    Public ReadOnly Property StartPageNumber As Integer
        Get
            Return StartIndex + 1
        End Get
    End Property

    Public ReadOnly Property EndPageNumber As Integer
        Get
            Return EndIndex + 1
        End Get
    End Property
End Class

Private Enum DetectedPageOrientation
    Portrait
    Landscape
End Enum