将 JPEG 转换为 PDF .NET：完整的 C# 开发人员指南

using IronPdf;
// Convert a single JPG image to PDF
string imagePath = "photo.jpg";
PdfDocument pdf = ImageToPdfConverter.ImageToPdf(imagePath);
// Save the converted PDF file
pdf.SaveAs("converted-photo.pdf");

Imports IronPdf
' Convert a single JPG image to PDF
Dim imagePath As String = "photo.jpg"
Dim pdf As PdfDocument = ImageToPdfConverter.ImageToPdf(imagePath)
' Save the converted PDF file
pdf.SaveAs("converted-photo.pdf")

using IronPdf;
using System.IO;
using System.Linq;
// Gather all JPG files from a folder
var imagePaths = Directory.EnumerateFiles("photos")
    .Where(f => f.EndsWith(".jpg") || f.EndsWith(".jpeg"));
// Convert multiple JPG images to a single PDF file
PdfDocument pdf = ImageToPdfConverter.ImageToPdf(imagePaths);
// Download or save the combined PDF
pdf.SaveAs("photo-collection.pdf");
// Optional: Add page numbers to the collection
pdf.AddTextHeaders("{page} of {total-pages}", 
    IronPdf.Editing.TextHeaderFooter.Alignment.Center);
pdf.SaveAs("photo-collection-numbered.pdf");

Imports IronPdf
Imports System.IO
Imports System.Linq

' Gather all JPG files from a folder
Dim imagePaths = Directory.EnumerateFiles("photos") _
    .Where(Function(f) f.EndsWith(".jpg") OrElse f.EndsWith(".jpeg"))

' Convert multiple JPG images to a single PDF file
Dim pdf As PdfDocument = ImageToPdfConverter.ImageToPdf(imagePaths)

' Download or save the combined PDF
pdf.SaveAs("photo-collection.pdf")

' Optional: Add page numbers to the collection
pdf.AddTextHeaders("{page} of {total-pages}", IronPdf.Editing.TextHeaderFooter.Alignment.Center)
pdf.SaveAs("photo-collection-numbered.pdf")

// Process images with custom settings
var pdfDocuments = new List<PdfDocument>();
foreach (var imagePath in imagePaths)
{
    var pdf = ImageToPdfConverter.ImageToPdf(imagePath, ImageBehavior.FitToPageAndMaintainAspectRatio);
    pdfDocuments.Add(pdf);
}
// Merge all PDFs into one
var combinedPdf = PdfDocument.Merge(pdfDocuments);
combinedPdf.SaveAs("custom-photo-collection.pdf");

' Process images with custom settings
Dim pdfDocuments As New List(Of PdfDocument)()
For Each imagePath In imagePaths
    Dim pdf = ImageToPdfConverter.ImageToPdf(imagePath, ImageBehavior.FitToPageAndMaintainAspectRatio)
    pdfDocuments.Add(pdf)
Next
' Merge all PDFs into one
Dim combinedPdf = PdfDocument.Merge(pdfDocuments)
combinedPdf.SaveAs("custom-photo-collection.pdf")

// Custom image placement example
var renderingOptions = new ImageToPdfRenderOptions
{
    ImageBehavior = ImageBehavior.FitToPageAndMaintainAspectRatio,
    PaperSize = PdfPaperSize.A4,
    MarginTop = 25,
    MarginBottom = 25,
    MarginLeft = 25,
    MarginRight = 25
};
PdfDocument pdf = ImageToPdfConverter.ImageToPdf(imagePath, renderingOptions);
// Add a watermark to the converted image
pdf.ApplyWatermark("<h2 style='color:red'>CONFIDENTIAL</h2>", 30, 
    VerticalAlignment.Middle, HorizontalAlignment.Center);

' Custom image placement example
Dim renderingOptions As New ImageToPdfRenderOptions With {
    .ImageBehavior = ImageBehavior.FitToPageAndMaintainAspectRatio,
    .PaperSize = PdfPaperSize.A4,
    .MarginTop = 25,
    .MarginBottom = 25,
    .MarginLeft = 25,
    .MarginRight = 25
}
Dim pdf As PdfDocument = ImageToPdfConverter.ImageToPdf(imagePath, renderingOptions)
' Add a watermark to the converted image
pdf.ApplyWatermark("<h2 style='color:red'>CONFIDENTIAL</h2>", 30, VerticalAlignment.Middle, HorizontalAlignment.Center)