2025-2026年为.NET选择PDF库时常见问题的疑难解答

using (Viewer viewer = new Viewer("input.pdf"))
{
    HtmlViewOptions htmlOptions = HtmlViewOptions.ForEmbeddedResources("page_{0}.html");
    viewer.View(htmlOptions);

    PngViewOptions pngOptions = new PngViewOptions("page_{0}.png");
    viewer.View(pngOptions);

    PdfViewOptions pdfOptions = new PdfViewOptions("rendered.pdf");
    viewer.View(pdfOptions);
}

Imports System

Using viewer As New Viewer("input.pdf")
    Dim htmlOptions As HtmlViewOptions = HtmlViewOptions.ForEmbeddedResources("page_{0}.html")
    viewer.View(htmlOptions)

    Dim pngOptions As New PngViewOptions("page_{0}.png")
    viewer.View(pngOptions)

    Dim pdfOptions As New PdfViewOptions("rendered.pdf")
    viewer.View(pdfOptions)
End Using

using (Converter converter = new Converter("input.docx"))
{
    PdfConvertOptions pdfOptions = new PdfConvertOptions
    {
        PdfOptions = new GroupDocs.Conversion.Options.Convert.PdfOptions
        {
            PdfFormat = GroupDocs.Conversion.FileTypes.PdfFileType.PdfA1A
        }
    };
    converter.Convert("output.pdf", pdfOptions);
}

Imports GroupDocs.Conversion
Imports GroupDocs.Conversion.Options.Convert

Using converter As New Converter("input.docx")
    Dim pdfOptions As New PdfConvertOptions With {
        .PdfOptions = New PdfOptions With {
            .PdfFormat = FileTypes.PdfFileType.PdfA1A
        }
    }
    converter.Convert("output.pdf", pdfOptions)
End Using

var renderer = new ChromePdfRenderer();
string html = @"<h1>Invoice 2026-0428</h1><p>Customer: Acme Corp</p><p>Total due: $1,240.00</p>";
using var pdf = renderer.RenderHtmlAsPdf(html);
pdf.SaveAs("invoice.pdf");

Dim renderer As New ChromePdfRenderer()
Dim html As String = "<h1>Invoice 2026-0428</h1><p>Customer: Acme Corp</p><p>Total due: $1,240.00</p>"
Using pdf = renderer.RenderHtmlAsPdf(html)
    pdf.SaveAs("invoice.pdf")
End Using

using (Annotator annotator = new Annotator("input.pdf"))
{
    AreaAnnotation area = new AreaAnnotation
    {
        Box = new Rectangle(100, 100, 200, 80),
        BackgroundColor = 65535,
        PageNumber = 0,
        Text = "Review this section"
    };
    annotator.Add(area);
    annotator.Save("annotated.pdf");
}

Imports System.Drawing

Using annotator As New Annotator("input.pdf")
    Dim area As New AreaAnnotation With {
        .Box = New Rectangle(100, 100, 200, 80),
        .BackgroundColor = 65535,
        .PageNumber = 0,
        .Text = "Review this section"
    }
    annotator.Add(area)
    annotator.Save("annotated.pdf")
End Using

using (Signature signature = new Signature("input.pdf"))
{
    TextSignOptions textOptions = new TextSignOptions("John Smith")
    {
        Left = 100, Top = 100, Width = 200, Height = 60,
        ForeColor = System.Drawing.Color.Black,
        Font = new SignatureFont { Size = 14, FamilyName = "Arial" }
    };
    signature.Sign("signed.pdf", textOptions);
}

Imports System.Drawing

Using signature As New Signature("input.pdf")
    Dim textOptions As New TextSignOptions("John Smith") With {
        .Left = 100,
        .Top = 100,
        .Width = 200,
        .Height = 60,
        .ForeColor = Color.Black,
        .Font = New SignatureFont With {.Size = 14, .FamilyName = "Arial"}
    }
    signature.Sign("signed.pdf", textOptions)
End Using

using (Redactor redactor = new Redactor("input.pdf"))
{
    ExactPhraseRedaction phraseRedaction = new ExactPhraseRedaction(
        "confidential",
        new ReplacementOptions("[REDACTED]")
    );
    redactor.Apply(phraseRedaction);
    redactor.Save();
}

Imports System

Using redactor As New Redactor("input.pdf")
    Dim phraseRedaction As New ExactPhraseRedaction("confidential", New ReplacementOptions("[REDACTED]"))
    redactor.Apply(phraseRedaction)
    redactor.Save()
End Using