如何在 PDF 式中设置字体 C#

# RemovePdfiumViewerpackages
dotnet remove package PdfiumViewer
dotnet remove package PdfiumViewer.Native.x86.v8-xfa
dotnet remove package PdfiumViewer.Native.x86_64.v8-xfa

# Install IronPDF
dotnet add package IronPdf

// Add at application startup (Program.cs or Startup.cs)
IronPdf.License.LicenseKey = "YOUR-LICENSE-KEY";

' Add at application startup (Program.vb or Startup.vb)
IronPdf.License.LicenseKey = "YOUR-LICENSE-KEY"

# FindPdfiumViewerusage
grep -r "PdfiumViewer\|PdfViewer\|PdfDocument\.Load" --include="*.cs" .

# Find native binary references
grep -r "pdfium\.dll\|Native\.x86\|Native\.x64" --include="*.csproj" .

# Find viewer control usage
grep -r "PdfViewer" --include="*.cs" --include="*.Designer.cs" .

// PdfiumViewer
using PdfiumViewer;

// IronPDF
using IronPdf;
using IronPdf.Rendering;
using IronPdf.Editing;

Imports PdfiumViewer

Imports IronPdf
Imports IronPdf.Rendering
Imports IronPdf.Editing

// NuGet: Install-Package PdfiumViewer
//        Install-Package PdfiumViewer.Native.x86.v8-xfa
//        Install-Package PdfiumViewer.Native.x86_64.v8-xfa
using PdfiumViewer;
using System;
using System.Text;

string pdfPath = "document.pdf";

//PdfiumViewerexposes page-level text extraction via
// PdfDocument.GetPdfText(int page). It returns raw page text only —
// no layout, no per-word coordinates, no OCR for image-only pages.
using (var document = PdfDocument.Load(pdfPath))
{
    int pageCount = document.PageCount;
    Console.WriteLine($"Total pages: {pageCount}");

    var sb = new StringBuilder();
    for (int i = 0; i < pageCount; i++)
    {
        string pageText = document.GetPdfText(i);
        sb.AppendLine($"--- Page {i + 1} ---");
        sb.AppendLine(pageText);
    }

    Console.WriteLine(sb.ToString());
}

Imports PdfiumViewer
Imports System
Imports System.Text

Dim pdfPath As String = "document.pdf"

' PdfiumViewer exposes page-level text extraction via
' PdfDocument.GetPdfText(Integer page). It returns raw page text only —
' no layout, no per-word coordinates, no OCR for image-only pages.
Using document As PdfDocument = PdfDocument.Load(pdfPath)
    Dim pageCount As Integer = document.PageCount
    Console.WriteLine($"Total pages: {pageCount}")

    Dim sb As New StringBuilder()
    For i As Integer = 0 To pageCount - 1
        Dim pageText As String = document.GetPdfText(i)
        sb.AppendLine($"--- Page {i + 1} ---")
        sb.AppendLine(pageText)
    Next

    Console.WriteLine(sb.ToString())
End Using

// NuGet: Install-Package IronPdf
using IronPdf;
using System;

string pdfPath = "document.pdf";

// Open and extract text from PDF
PdfDocument pdf = PdfDocument.FromFile(pdfPath);

// Extract text from all pages
string allText = pdf.ExtractAllText();
Console.WriteLine("Extracted Text:");
Console.WriteLine(allText);

// Extract text from specific page
string pageText = pdf.ExtractTextFromPage(0);
Console.WriteLine($"\nFirst page text: {pageText}");

Console.WriteLine($"\nTotal pages: {pdf.PageCount}");

Imports IronPdf
Imports System

Module Program
    Sub Main()
        Dim pdfPath As String = "document.pdf"

        ' Open and extract text from PDF
        Dim pdf As PdfDocument = PdfDocument.FromFile(pdfPath)

        ' Extract text from all pages
        Dim allText As String = pdf.ExtractAllText()
        Console.WriteLine("Extracted Text:")
        Console.WriteLine(allText)

        ' Extract text from specific page
        Dim pageText As String = pdf.ExtractTextFromPage(0)
        Console.WriteLine(vbCrLf & "First page text: " & pageText)

        Console.WriteLine(vbCrLf & "Total pages: " & pdf.PageCount)
    End Sub
End Module

// NuGet: Install-Package PdfiumViewer
using PdfiumViewer;
using System;

//PdfiumViewerwraps Google's PDFium — a renderer, not a generator.
// PDFium does not parse HTML, soPdfiumViewerhas no HTML-to-PDF path.
// To produce a PDF from HTML you need a separate generator (wkhtmltopdf,
// IronPDF, PuppeteerSharp, etc.), then load the result with PdfiumViewer
// for display or rasterization.

string htmlContent = "<h1>Hello World</h1><p>This is a test document.</p>";

// Pretend "output.pdf" was produced by another tool — load and render it.
string existingPdfPath = "output.pdf";
using (var document = PdfDocument.Load(existingPdfPath))
{
    Console.WriteLine($"Loaded PDF with {document.PageCount} page(s).");

    // PdfDocument.Render(int page, float dpiX, float dpiY, bool forPrinting)
    var image = document.Render(0, 300, 300, true);
    Console.WriteLine("Rendered page 1 at 300 DPI.");
}

Imports PdfiumViewer
Imports System

' PdfiumViewer wraps Google's PDFium — a renderer, not a generator.
' PDFium does not parse HTML, so PdfiumViewer has no HTML-to-PDF path.
' To produce a PDF from HTML you need a separate generator (wkhtmltopdf,
' IronPDF, PuppeteerSharp, etc.), then load the result with PdfiumViewer
' for display or rasterization.

Dim htmlContent As String = "<h1>Hello World</h1><p>This is a test document.</p>"

' Pretend "output.pdf" was produced by another tool — load and render it.
Dim existingPdfPath As String = "output.pdf"
Using document As PdfDocument = PdfDocument.Load(existingPdfPath)
    Console.WriteLine($"Loaded PDF with {document.PageCount} page(s).")

    ' PdfDocument.Render(int page, float dpiX, float dpiY, bool forPrinting)
    Dim image = document.Render(0, 300, 300, True)
    Console.WriteLine("Rendered page 1 at 300 DPI.")
End Using

// NuGet: Install-Package IronPdf
using IronPdf;
using System;

string htmlContent = "<h1>Hello World</h1><p>This is a test document.</p>";

// Create a PDF from HTML string
var renderer = new ChromePdfRenderer();
PdfDocument pdf = renderer.RenderHtmlAsPdf(htmlContent);

// Save the PDF
pdf.SaveAs("output.pdf");

Console.WriteLine("PDF created successfully!");

Imports IronPdf
Imports System

Module Program
    Sub Main()
        Dim htmlContent As String = "<h1>Hello World</h1><p>This is a test document.</p>"

        ' Create a PDF from HTML string
        Dim renderer As New ChromePdfRenderer()
        Dim pdf As PdfDocument = renderer.RenderHtmlAsPdf(htmlContent)

        ' Save the PDF
        pdf.SaveAs("output.pdf")

        Console.WriteLine("PDF created successfully!")
    End Sub
End Module

// NuGet: Install-Package PdfiumViewer
using PdfiumViewer;
using System;
using System.Drawing;
using System.Drawing.Imaging;

string pdfPath = "document.pdf";
string outputImage = "page1.png";

// PDFiumViewer excels at rendering PDFs to images
using (var document = PdfDocument.Load(pdfPath))
{
    // Render first page at 300 DPI
    int dpi = 300;
    using (var image = document.Render(0, dpi, dpi, true))
    {
        // Save as PNG
        image.Save(outputImage, ImageFormat.Png);
        Console.WriteLine($"Page rendered to {outputImage}");
    }

    // Render all pages
    for (int i = 0; i < document.PageCount; i++)
    {
        using (var pageImage = document.Render(i, 150, 150, true))
        {
            pageImage.Save($"page_{i + 1}.png", ImageFormat.Png);
        }
    }
}

Imports PdfiumViewer
Imports System
Imports System.Drawing
Imports System.Drawing.Imaging

Module Module1
    Sub Main()
        Dim pdfPath As String = "document.pdf"
        Dim outputImage As String = "page1.png"

        ' PDFiumViewer excels at rendering PDFs to images
        Using document = PdfDocument.Load(pdfPath)
            ' Render first page at 300 DPI
            Dim dpi As Integer = 300
            Using image = document.Render(0, dpi, dpi, True)
                ' Save as PNG
                image.Save(outputImage, ImageFormat.Png)
                Console.WriteLine($"Page rendered to {outputImage}")
            End Using

            ' Render all pages
            For i As Integer = 0 To document.PageCount - 1
                Using pageImage = document.Render(i, 150, 150, True)
                    pageImage.Save($"page_{i + 1}.png", ImageFormat.Png)
                End Using
            Next
        End Using
    End Sub
End Module

// NuGet: Install-Package IronPdf
using IronPdf;
using System;
using System.Linq;

string pdfPath = "document.pdf";
string outputImage = "page1.png";

// Open PDF and convert to images
PdfDocument pdf = PdfDocument.FromFile(pdfPath);

// Convert first page to image
var firstPageImage = pdf.ToBitmap(0);
firstPageImage[0].Save(outputImage);
Console.WriteLine($"Page rendered to {outputImage}");

// Convert all pages to images
var allPageImages = pdf.ToBitmap();
for (int i = 0; i < allPageImages.Length; i++)
{
    allPageImages[i].Save($"page_{i + 1}.png");
    Console.WriteLine($"Saved page {i + 1}");
}

Console.WriteLine($"Total pages converted: {pdf.PageCount}");

Imports IronPdf
Imports System
Imports System.Linq

Module Module1
    Sub Main()
        Dim pdfPath As String = "document.pdf"
        Dim outputImage As String = "page1.png"

        ' Open PDF and convert to images
        Dim pdf As PdfDocument = PdfDocument.FromFile(pdfPath)

        ' Convert first page to image
        Dim firstPageImage = pdf.ToBitmap(0)
        firstPageImage(0).Save(outputImage)
        Console.WriteLine($"Page rendered to {outputImage}")

        ' Convert all pages to images
        Dim allPageImages = pdf.ToBitmap()
        For i As Integer = 0 To allPageImages.Length - 1
            allPageImages(i).Save($"page_{i + 1}.png")
            Console.WriteLine($"Saved page {i + 1}")
        Next

        Console.WriteLine($"Total pages converted: {pdf.PageCount}")
    End Sub
End Module

# Delete native PDFium binaries
rm -rf x86/x64/runtimes/

# Remove from .csproj native package references
# <PackageReference Include="PdfiumViewer.Native.x86.v8-xfa" />
# <PackageReference Include="PdfiumViewer.Native.x64.v8-xfa" />

// PdfiumViewer: Built-in viewer control
pdfViewer.Document = document;

// IronPDF: Use external viewer or web-based approach
pdf.SaveAs(tempPath);
Process.Start(new ProcessStartInfo(tempPath) { UseShellExecute = true });

' PdfiumViewer: Built-in viewer control
pdfViewer.Document = document

' IronPDF: Use external viewer or web-based approach
pdf.SaveAs(tempPath)
Process.Start(New ProcessStartInfo(tempPath) With {.UseShellExecute = True})

// PdfiumViewer
PdfDocument.Load(path)

// IronPDF
PdfDocument.FromFile(path)

' PdfiumViewer
PdfDocument.Load(path)

' IronPDF
PdfDocument.FromFile(path)

// PdfiumViewer
document.Save(path)

// IronPDF
pdf.SaveAs(path)

// PdfiumViewer: Returns image with nested using
using (var image = document.Render(0, 150, 150, true))
{
    image.Save("page.png", ImageFormat.Png);
}

// IronPDF: Returns bitmap array
var images = pdf.ToBitmap(0);
images[0].Save("page.png");

Imports System.Drawing.Imaging

' PdfiumViewer: Returns image with nested using
Using image = document.Render(0, 150, 150, True)
    image.Save("page.png", ImageFormat.Png)
End Using

' IronPDF: Returns bitmap array
Dim images = pdf.ToBitmap(0)
images(0).Save("page.png")

// PdfiumViewer
var size = document.PageSizes[index];
Console.WriteLine($"{size.Width} x {size.Height}");

// IronPDF
var page = pdf.Pages[index];
Console.WriteLine($"{page.Width} x {page.Height}");

' PdfiumViewer
Dim size = document.PageSizes(index)
Console.WriteLine($"{size.Width} x {size.Height}")

' IronPDF
Dim page = pdf.Pages(index)
Console.WriteLine($"{page.Width} x {page.Height}")