探索PDFsharp向PDF新增水印的最佳替代方案

using IronPdf;

class Program
{
    static void Main()
    {
        // Load an existing PDF document.
        PdfDocument pdf = PdfDocument.FromFile("existing.pdf");

        // Define the watermark using HTML and CSS.
        string watermark = "<img src='https://ironsoftware.com/img/products/ironpdf-logo-text-dotnet.svg'><h1 style='color:red;'>CONFIDENTIAL</h1>";

        // Apply the watermark with specified rotation and opacity.
        pdf.ApplyWatermark(watermark, rotation: 45, opacity: 80);

        // Save the watermarked document.
        pdf.SaveAs("watermarked.pdf");
    }
}

Imports IronPdf

Friend Class Program
	Shared Sub Main()
		' Load an existing PDF document.
		Dim pdf As PdfDocument = PdfDocument.FromFile("existing.pdf")

		' Define the watermark using HTML and CSS.
		Dim watermark As String = "<img src='https://ironsoftware.com/img/products/ironpdf-logo-text-dotnet.svg'><h1 style='color:red;'>CONFIDENTIAL</h1>"

		' Apply the watermark with specified rotation and opacity.
		pdf.ApplyWatermark(watermark, rotation:= 45, opacity:= 80)

		' Save the watermarked document.
		pdf.SaveAs("watermarked.pdf")
	End Sub
End Class

using QuestPDF.Fluent;
using QuestPDF.Helpers;
using QuestPDF.Infrastructure;

public class WatermarkExample
{
    public static void Main()
    {
        // Set the license type to Community for QuestPDF.
        QuestPDF.Settings.License = LicenseType.Community;

        // Create a PDF document with a defined structure.
        Document.Create(container =>
        {
            container.Page(page =>
            {
                page.Margin(50);

                // Add a foreground watermark.
                page.Foreground().Element(watermark =>
                {
                    watermark.Text("DRAFT")
                        .FontSize(40)
                        .FontColor(Colors.Red.Medium)
                        .AlignLeft();
                });

                // Add the main content of the page.
                page.Content().Element(ComposeContent);
            });
        })
        .GeneratePdf("watermarked_document.pdf");
    }

    private static IContainer ComposeContent(IContainer container)
    {
        // Define the layout and content of the PDF.
        container.Column(column =>
        {
            column.Spacing(10);
            column.Item().Text("This is the main content of the PDF.");
            column.Item().Text("Add more content as needed.");
        });

        return container; // Return the container to maintain method signature.
    }
}

Imports QuestPDF.Fluent
Imports QuestPDF.Helpers
Imports QuestPDF.Infrastructure

Public Class WatermarkExample
	Public Shared Sub Main()
		' Set the license type to Community for QuestPDF.
		QuestPDF.Settings.License = LicenseType.Community

		' Create a PDF document with a defined structure.
		Document.Create(Sub(container)
			container.Page(Sub(page)
				page.Margin(50)

				' Add a foreground watermark.
				page.Foreground().Element(Sub(watermark)
					watermark.Text("DRAFT").FontSize(40).FontColor(Colors.Red.Medium).AlignLeft()
				End Sub)

				' Add the main content of the page.
				page.Content().Element(AddressOf ComposeContent)
			End Sub)
		End Sub).GeneratePdf("watermarked_document.pdf")
	End Sub

	Private Shared Function ComposeContent(ByVal container As IContainer) As IContainer
		' Define the layout and content of the PDF.
		container.Column(Sub(column)
			column.Spacing(10)
			column.Item().Text("This is the main content of the PDF.")
			column.Item().Text("Add more content as needed.")
		End Sub)

		Return container ' Return the container to maintain method signature.
	End Function
End Class