Les impressions PDF à orientations mixtes impriment chaque page au format paysage
IronPrint 2026.1.5 ne préserve pas l'orientation par page lors de l'impression d'un PDF qui mélange des pages en portrait et en paysage. Chaque page atteint l'imprimante au format paysage, quelle que soit son orientation originale.
Cela affecte 2026.1.5 sur Windows 10 et Windows Server 2022 sous .NET 8. Aucun correctif n'existe pour cette version.
Le moteur applique une seule orientation à l'ensemble du document au lieu de lire les dimensions de chaque page. Diviser le fichier en lots de pages de même orientation et imprimer chaque lot séparément rétablit la sortie correcte.
Solution
Recommandé : imprimez le PDF par lots cohérents en termes d'orientation au lieu de le faire en une seule opération.
1. Détecter l'orientation de chaque page
Ouvrez le PDF et comparez la largeur de chaque page à sa hauteur. Une page plus large que haute est au format paysage ; tout le reste est au format portrait.
2. Regroupez les pages ayant la même orientation consécutive
Parcourez les pages dans l'ordre et commencez un nouveau lot chaque fois que l'orientation change. Chaque lot finit par être une plage de pages contiguës avec une orientation.
3. Imprimez chaque lot comme une opération distincte
Envoyer chaque plage séparément permet à l'imprimante d'appliquer l'orientation de cette plage, plutôt que de forcer l'ensemble du document au format paysage.
4. Gérez les copies multiples manuellement
Étant donné que le document est maintenant divisé en plusieurs travaux, bouclez une fois par copie et imprimez la séquence complète des lots chaque fois. Cela préserve l'ordre des pages pour chaque copie.
Implémentation complète :
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
}
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
GetConsecutiveOrientationBatches produit un PageOrientationBatch par série contiguë, et Printer.PrintAsync exécute chaque plage avec son propre PaperOrientation. Le Task.Delay(500) entre les travaux aide le spooler à les mettre en file d'attente dans l'ordre.

