C#使用PdfiumViewer库处理PDF文件的实践方法

dotnet add package PdfiumViewer

dotnet add package PdfiumViewer.Native.x64

using PdfiumViewer;

using (var document = PdfDocument.Load("sample.pdf"))
{
    int pageCount = document.PageCount;
    Console.WriteLine($"PDF 页数：{pageCount}");
}

using PdfiumViewer;
using System.Drawing;

using (var document = PdfDocument.Load("sample.pdf"))
{
    int pageIndex = 0;

    // 300 DPI 高清渲染
    var image = document.Render(
        pageIndex,
        300,
        300,
        PdfRenderFlags.Annotations
    );

    image.Save("page1.png", System.Drawing.Imaging.ImageFormat.Png);
}

using PdfiumViewer;
using System.Drawing.Imaging;

void ConvertPdfToImages(string pdfPath, string outputDir)
{
    using var document = PdfDocument.Load(pdfPath);

    Directory.CreateDirectory(outputDir);

    for (int i = 0; i < document.PageCount; i++)
    {
        using var image = document.Render(i, 300, 300, PdfRenderFlags.Annotations);
        string path = Path.Combine(outputDir, $"page_{i + 1}.jpg");
        image.Save(path, ImageFormat.Jpeg);
    }
}

using PdfiumViewer;

using var document = PdfDocument.Load("sample.pdf");

var size = document.PageSizes[0];

Console.WriteLine($"宽：{size.Width} pt");
Console.WriteLine($"高：{size.Height} pt");

int dpi = 300;
int widthPx = (int)(size.Width / 72 * dpi);
int heightPx = (int)(size.Height / 72 * dpi);

using PdfiumViewer;

using var document = PdfDocument.Load("sample.pdf");

string text = document.GetPdfText(0);
Console.WriteLine(text);

using PdfiumViewer;

PdfDocument document = PdfDocument.Load("sample.pdf");

pictureBox1.Image = document.Render(
    0,
    pictureBox1.Width,
    pictureBox1.Height,
    true
);

using PdfiumViewer;
using System.Drawing;

using var document = PdfDocument.Load("sample.pdf");

var pageSize = document.PageSizes[0];

RectangleF crop = new RectangleF(
    0,
    0,
    pageSize.Width / 2,
    pageSize.Height / 2
);

using var image = document.Render(
    0,
    300,
    300,
    crop,
    PdfRenderFlags.None
);

image.Save("crop.png");