Printing: Use –FPDF_RenderPage instead of FPDF_RenderPageBitmap to allow vector graphics
Test / Run tests (push) Successful in 2m38s

This commit is contained in:
2026-08-10 18:35:49 +02:00
parent f13a836ebd
commit 20b19775b1
6 changed files with 365 additions and 118 deletions
+1 -1
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@@ -23,7 +23,7 @@
</ItemGroup>
<ItemGroup>
<PackageReference Include="bblanchon.PDFium.Win32" Version="153.0.7988" />
<PackageReference Include="bblanchon.PDFium.Win32" Version="153.0.7999" />
<PackageReference Include="CommunityToolkit.Mvvm" Version="8.4.2" />
<PackageReference Include="itext" Version="9.7.0" />
<PackageReference Include="itext.bouncy-castle-adapter" Version="9.7.0" />
+3 -14
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@@ -1,7 +1,6 @@
using Elwig.Services;
using Elwig.Windows;
using System;
using System.Drawing.Printing;
using System.Threading.Tasks;
namespace Elwig.Helpers.Printing {
@@ -32,20 +31,10 @@ namespace Elwig.Helpers.Printing {
});
}
public static async Task Print(string path, int copies = 1, bool doublePaged = false) {
await Print(path, new() {
Copies = (short)copies,
Collate = true,
Duplex = doublePaged ? Duplex.Vertical : Duplex.Simplex,
});
}
public static Task Print(string path, PrinterSettings settings) {
public static Task Print(string path, int copies = 1, bool doublePaged = false) {
try {
using var printDoc = new PdfPrintDocument(path) {
PrinterSettings = settings,
};
printDoc.Print();
var printer = new PdfPrinter();
printer.Print(path, copies, doublePaged);
} catch (Exception exc) {
InteractionService.ShowException("Fehler beim Drucken", "Beim Drucken ist ein Fehler aufgetreten", exc);
}
-103
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@@ -1,103 +0,0 @@
using System;
using System.Drawing;
using System.Drawing.Imaging;
using System.Drawing.Printing;
using System.Runtime.InteropServices;
namespace Elwig.Helpers.Printing {
public class PdfPrintDocument : PrintDocument {
private readonly IntPtr _handle;
private readonly int _pageCount;
private int _currentPage;
public PdfPrintDocument(string path, string? password = null) :
base() {
_handle = PdfiumNative.FPDF_LoadDocument(path, password);
_pageCount = PdfiumNative.FPDF_GetPageCount(_handle);
}
protected override void Dispose(bool disposing) {
PdfiumNative.FPDF_CloseDocument(_handle);
base.Dispose(disposing);
}
protected override void OnBeginPrint(PrintEventArgs evt) {
_currentPage = (PrinterSettings.FromPage != 0) ? (PrinterSettings.FromPage - 1) : 0;
base.OnBeginPrint(evt);
}
protected override void OnPrintPage(PrintPageEventArgs evt) {
if (_currentPage < _pageCount) {
IntPtr page = PdfiumNative.FPDF_LoadPage(_handle, _currentPage);
double width = PdfiumNative.FPDF_GetPageWidth(page);
double height = PdfiumNative.FPDF_GetPageHeight(page);
int pixelWidth = (int)(width / 72.0 * (evt.Graphics?.DpiX ?? 300.0));
int pixelHeight = (int)(height / 72.0 * (evt.Graphics?.DpiY ?? 300.0));
IntPtr bitmap = PdfiumNative.FPDFBitmap_Create(pixelWidth, pixelHeight, 1);
PdfiumNative.FPDF_RenderPageBitmap(bitmap, page, 0, 0, pixelWidth, pixelHeight, 0, 0);
IntPtr buffer = PdfiumNative.FPDFBitmap_GetBuffer(bitmap);
int stride = PdfiumNative.FPDFBitmap_GetStride(bitmap);
using (var bmp = new Bitmap(pixelWidth, pixelHeight, stride, PixelFormat.Format32bppArgb, buffer)) {
evt.Graphics?.TranslateTransform(
-evt.PageSettings.HardMarginX,
-evt.PageSettings.HardMarginY);
evt.Graphics?.DrawImage(bmp, new RectangleF(0, 0, (float)(width / 72.0 * 100.0), (float)(height / 72.0 * 100.0)));
}
_currentPage++;
PdfiumNative.FPDFBitmap_Destroy(bitmap);
PdfiumNative.FPDF_ClosePage(page);
}
evt.HasMorePages = _currentPage < ((PrinterSettings.ToPage == 0) ? _pageCount : Math.Min(PrinterSettings.ToPage, _pageCount));
base.OnPrintPage(evt);
}
}
internal partial class PdfiumNative {
[LibraryImport("pdfium.dll")]
public static partial void FPDF_InitLibrary();
[LibraryImport("pdfium.dll")]
public static partial void FPDF_DestroyLibrary();
[LibraryImport("pdfium.dll", StringMarshalling = StringMarshalling.Utf8)]
public static partial IntPtr FPDF_LoadDocument(string filePath, string? password);
[LibraryImport("pdfium.dll")]
public static partial void FPDF_CloseDocument(IntPtr document);
[LibraryImport("pdfium.dll")]
public static partial int FPDF_GetPageCount(IntPtr document);
[LibraryImport("pdfium.dll")]
public static partial IntPtr FPDF_LoadPage(IntPtr document, int pageIndex);
[LibraryImport("pdfium.dll")]
public static partial void FPDF_ClosePage(IntPtr page);
[LibraryImport("pdfium.dll")]
public static partial double FPDF_GetPageWidth(IntPtr page);
[LibraryImport("pdfium.dll")]
public static partial double FPDF_GetPageHeight(IntPtr page);
[LibraryImport("pdfium.dll")]
public static partial IntPtr FPDFBitmap_Create(int width, int height, int alpha);
[LibraryImport("pdfium.dll")]
public static partial void FPDFBitmap_Destroy(IntPtr bitmap);
[LibraryImport("pdfium.dll")]
public static partial IntPtr FPDFBitmap_GetBuffer(IntPtr bitmap);
[LibraryImport("pdfium.dll")]
public static partial int FPDFBitmap_GetStride(IntPtr bitmap);
[LibraryImport("pdfium.dll")]
public static partial void FPDF_RenderPageBitmap(IntPtr bitmap, IntPtr page, int start_x, int start_y, int size_x, int size_y, int rotate, int flags);
}
}
+94
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@@ -0,0 +1,94 @@
using System;
using System.IO;
using System.Printing;
namespace Elwig.Helpers.Printing {
public class PdfPrinter {
public string PrinterName { get; init; }
public PdfPrinter(string? printerName = null) {
PrinterName = printerName ?? GetDefaultPrinterName() ?? throw new InvalidOperationException("No default Windows printer is configured.");
}
public void Print(string pdfPath, int copies = 1, bool doublePaged = false) {
if (!File.Exists(pdfPath)) throw new FileNotFoundException("PDF file not found.", pdfPath);
IntPtr document = PdfiumNative.FPDF_LoadDocument(pdfPath, null);
if (document == IntPtr.Zero) throw new InvalidOperationException("PDFium could not open the PDF.");
try {
int pageCount = PdfiumNative.FPDF_GetPageCount(document);
if (pageCount <= 0)
return;
using var printer = new Win32Printer.Printer(PrinterName);
printer.TrySetDuplex(doublePaged ? Duplexing.TwoSidedLongEdge : Duplexing.OneSided);
for (int i = 0; i < copies; i++) {
printer.StartDocument(Path.GetFileName(pdfPath));
bool documentStarted = true;
try {
for (int j = 0; j < pageCount; j++) {
PrintPage(document, printer, j);
}
printer.EndDocument();
documentStarted = false;
} finally {
if (documentStarted) printer.AbortDocument();
}
}
} finally {
PdfiumNative.FPDF_CloseDocument(document);
}
}
private static void PrintPage(IntPtr document, Win32Printer.Printer printer, int pageIndex) {
if (!PdfiumNative.FPDF_GetPageSizeByIndex(document, pageIndex, out double pageWidthPt, out double pageHeightPt)) {
throw new InvalidOperationException($"Unable to obtain PDF page {pageIndex} size.");
}
IntPtr page = PdfiumNative.FPDF_LoadPage(document, pageIndex);
if (page == IntPtr.Zero)
throw new InvalidOperationException($"Unable to load PDF page {pageIndex}.");
try {
// PDF coordinates are points (1/72 inch).
//
// HORZRES/VERTRES are the printable area in
// device pixels for the current printer DC.
int widthPx = printer.PixelWidth;
int heightPx = printer.PixelHeight;
// Preserve aspect ratio.
double scaleX = widthPx / pageWidthPt;
double scaleY = heightPx / pageHeightPt;
double scale = Math.Min(scaleX, scaleY);
int renderWidth = Math.Max(1, (int)Math.Round(pageWidthPt * scale));
int renderHeight = Math.Max(1, (int)Math.Round(pageHeightPt * scale));
int offsetX = (widthPx - renderWidth) / 2;
int offsetY = (heightPx - renderHeight) / 2;
printer.StartPage();
try {
PdfiumNative.FPDF_RenderPage(printer.Hdc, page, offsetX, offsetY, renderWidth, renderHeight, 0, PdfiumNative.FPDF_PRINTING | PdfiumNative.FPDF_ANNOT);
} finally {
printer.EndPage();
}
} finally {
PdfiumNative.FPDF_ClosePage(page);
}
}
private static string? GetDefaultPrinterName() {
using var key = Microsoft.Win32.Registry.CurrentUser.OpenSubKey(@"Software\Microsoft\Windows NT\CurrentVersion\Windows");
string? printer = key?.GetValue("Device") as string;
if (string.IsNullOrWhiteSpace(printer))
return null;
// Device has the form:
// Printer Name,winspool,PORT
int comma = printer.IndexOf(',');
return comma >= 0 ? printer[..comma] : printer;
}
}
}
+38
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@@ -0,0 +1,38 @@
using System;
using System.Runtime.InteropServices;
namespace Elwig.Helpers.Printing {
internal partial class PdfiumNative {
public const int FPDF_ANNOT = 0x01;
public const int FPDF_PRINTING = 0x800;
[LibraryImport("pdfium.dll")]
public static partial void FPDF_InitLibrary();
[LibraryImport("pdfium.dll")]
public static partial void FPDF_DestroyLibrary();
[LibraryImport("pdfium.dll", StringMarshalling = StringMarshalling.Utf8)]
public static partial IntPtr FPDF_LoadDocument(string filePath, string? password);
[LibraryImport("pdfium.dll")]
public static partial void FPDF_CloseDocument(IntPtr document);
[LibraryImport("pdfium.dll")]
public static partial int FPDF_GetPageCount(IntPtr document);
[LibraryImport("pdfium.dll")]
public static partial IntPtr FPDF_LoadPage(IntPtr document, int pageIndex);
[LibraryImport("pdfium.dll")]
public static partial void FPDF_ClosePage(IntPtr page);
[LibraryImport("pdfium.dll")]
[return: MarshalAs(UnmanagedType.Bool)]
public static partial bool FPDF_GetPageSizeByIndex(IntPtr document, int pageIndex, out double width, out double height);
[LibraryImport("pdfium.dll")]
public static partial void FPDF_RenderPage(IntPtr hdc, IntPtr page, int startX, int startY, int sizeX, int sizeY, int rotate, int flags);
}
}
+229
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@@ -0,0 +1,229 @@
using System;
using System.ComponentModel;
using System.Printing;
using System.Runtime.InteropServices;
namespace Elwig.Helpers.Printing {
public partial class Win32Printer {
private const int DM_OUT_BUFFER = 2;
private const int HORZRES = 8;
private const int VERTRES = 10;
private const int LOGPIXELSX = 88;
private const int LOGPIXELSY = 90;
private const int DM_DUPLEX = 0x1000;
private const short DMDUP_SIMPLEX = 1;
private const short DMDUP_VERTICAL = 2;
private const short DMDUP_HORIZONTAL = 3;
[StructLayout(LayoutKind.Sequential, CharSet = CharSet.Unicode)]
private struct DOCINFO {
public int cbSize;
[MarshalAs(UnmanagedType.LPWStr)]
public string? lpszDocName;
[MarshalAs(UnmanagedType.LPWStr)]
public string? lpszOutput;
[MarshalAs(UnmanagedType.LPWStr)]
public string? lpszDatatype;
}
[StructLayout(LayoutKind.Sequential, CharSet = CharSet.Unicode)]
private struct DEVMODE {
[MarshalAs(UnmanagedType.ByValTStr, SizeConst = 32)]
public string dmDeviceName;
public short dmSpecVersion;
public short dmDriverVersion;
public short dmSize;
public short dmDriverExtra;
public int dmFields;
public short dmOrientation;
public short dmPaperSize;
public short dmPaperLength;
public short dmPaperWidth;
public short dmScale;
public short dmCopies;
public short dmDefaultSource;
public short dmPrintQuality;
public short dmColor;
public short dmDuplex;
public short dmYResolution;
public short dmTTOption;
public short dmCollate;
[MarshalAs(UnmanagedType.ByValTStr, SizeConst = 32)]
public string dmFormName;
public short dmLogPixels;
public int dmBitsPerPel;
public int dmPelsWidth;
public int dmPelsHeight;
public int dmDisplayFlags;
public int dmDisplayFrequency;
public int dmICMMethod;
public int dmICMIntent;
public int dmMediaType;
public int dmDitherType;
public int dmReserved1;
public int dmReserved2;
public int dmPanningWidth;
public int dmPanningHeight;
}
[DllImport("winspool.drv", SetLastError = true, CharSet = CharSet.Unicode)]
private static extern bool OpenPrinter(string pPrinterName, out IntPtr phPrinter, IntPtr pDefault);
[DllImport("winspool.drv", SetLastError = true)]
private static extern bool ClosePrinter(IntPtr hPrinter);
[DllImport("winspool.drv", SetLastError = true, CharSet = CharSet.Unicode)]
private static extern int DocumentProperties(IntPtr hwnd, IntPtr hPrinter, string pDeviceName, IntPtr pDevModeOutput, IntPtr pDevModeInput, int fMode);
[DllImport("gdi32.dll", SetLastError = true, CharSet = CharSet.Unicode)]
private static extern IntPtr CreateDC(string? pDriver, string? pDevice, string? pOutput, IntPtr pInitData);
[DllImport("gdi32.dll", SetLastError = true)]
private static extern bool DeleteDC(IntPtr hdc);
[DllImport("gdi32.dll", SetLastError = true)]
private static extern int GetDeviceCaps(IntPtr hdc, int index);
[DllImport("gdi32.dll", SetLastError = true, CharSet = CharSet.Unicode)]
private static extern int StartDoc(IntPtr hdc, ref DOCINFO lpdi);
[DllImport("gdi32.dll", SetLastError = true)]
private static extern int EndDoc(IntPtr hdc);
[DllImport("gdi32.dll", SetLastError = true)]
private static extern int AbortDoc(IntPtr hdc);
[DllImport("gdi32.dll", SetLastError = true)]
private static extern int StartPage(IntPtr hdc);
[DllImport("gdi32.dll", SetLastError = true)]
private static extern int EndPage(IntPtr hdc);
[DllImport("kernel32.dll", SetLastError = true)]
private static extern IntPtr GlobalAlloc(uint uFlags, UIntPtr dwBytes);
[DllImport("kernel32.dll", SetLastError = true)]
private static extern IntPtr GlobalFree(IntPtr hMem);
[DllImport("kernel32.dll")]
private static extern IntPtr GlobalLock(IntPtr hMem);
[DllImport("kernel32.dll")]
private static extern bool GlobalUnlock(IntPtr hMem);
public class Printer : IDisposable {
private readonly string _printerName;
private readonly IntPtr _printerHandle;
private readonly IntPtr _devMode;
private readonly IntPtr _hdc;
public IntPtr Hdc => _hdc;
public int PixelWidth => GetDeviceCaps(_hdc, HORZRES);
public int PixelHeight => GetDeviceCaps(_hdc, VERTRES);
public int DpiX => GetDeviceCaps(_hdc, LOGPIXELSX);
public int DpiY => GetDeviceCaps(_hdc, LOGPIXELSY);
public Printer(string printerName) {
_printerName = printerName;
if (!OpenPrinter(_printerName, out _printerHandle, IntPtr.Zero)) {
throw new Win32Exception(Marshal.GetLastWin32Error(), $"Unable to open printer '{printerName}'.");
}
try {
_devMode = CreateDevMode();
_hdc = CreateDC(null, _printerName, null, _devMode);
if (_hdc == IntPtr.Zero)
throw new Win32Exception(Marshal.GetLastWin32Error(), $"Unable to create printer DC for '{_printerName}'.");
} catch {
if (_devMode != IntPtr.Zero) Marshal.FreeHGlobal(_devMode);
ClosePrinter(_printerHandle);
throw;
}
}
public bool TrySetDuplex(Duplexing duplex) {
var devMode = Marshal.PtrToStructure<DEVMODE>(_devMode);
if ((devMode.dmFields & DM_DUPLEX) != 0) {
switch (duplex) {
case Duplexing.OneSided: devMode.dmDuplex = DMDUP_SIMPLEX; break;
case Duplexing.TwoSidedShortEdge: devMode.dmDuplex = DMDUP_HORIZONTAL; break;
case Duplexing.TwoSidedLongEdge: devMode.dmDuplex = DMDUP_VERTICAL; break;
}
Marshal.StructureToPtr(devMode, _devMode, false);
return true;
} else {
return false;
}
}
private IntPtr CreateDevMode() {
int size = DocumentProperties(IntPtr.Zero, _printerHandle, _printerName, IntPtr.Zero, IntPtr.Zero, 0);
if (size <= 0)
throw new Win32Exception(Marshal.GetLastWin32Error(), "DocumentProperties failed.");
IntPtr devMode = Marshal.AllocHGlobal(size);
int result = DocumentProperties(IntPtr.Zero, _printerHandle, _printerName, devMode, IntPtr.Zero, DM_OUT_BUFFER);
if (result < 0) {
Marshal.FreeHGlobal(devMode);
throw new Win32Exception(Marshal.GetLastWin32Error(), "Unable to obtain printer DEVMODE.");
}
return devMode;
}
public void StartDocument(string documentName) {
var docInfo = new DOCINFO {
cbSize = Marshal.SizeOf<DOCINFO>(),
lpszDocName = documentName,
lpszDatatype = null,
lpszOutput = null
};
if (StartDoc(_hdc, ref docInfo) <= 0)
throw new Win32Exception(Marshal.GetLastWin32Error(), "StartDoc failed.");
}
public void StartPage() {
if (Win32Printer.StartPage(_hdc) <= 0)
throw new Win32Exception(Marshal.GetLastWin32Error(), "StartPage failed.");
}
public void EndPage() {
if (Win32Printer.EndPage(_hdc) <= 0)
throw new Win32Exception(Marshal.GetLastWin32Error(), "EndPage failed.");
}
public void EndDocument() {
if (EndDoc(_hdc) <= 0)
throw new Win32Exception( Marshal.GetLastWin32Error(), "EndDoc failed.");
}
public void AbortDocument() {
AbortDoc(_hdc);
}
public void Dispose() {
if (_hdc != IntPtr.Zero)
DeleteDC(_hdc);
if (_devMode != IntPtr.Zero)
Marshal.FreeHGlobal(_devMode);
if (_printerHandle != IntPtr.Zero)
ClosePrinter(_printerHandle);
}
}
}
}