pdf 转 png

https://gitee.com/GVIEW/PdfiumViewer.Core

NuGet

Install-Package PdfiumViewer.Core

Install-Package PdfiumViewer.Native.x86_64.v8-xfa
Install-Package PdfiumViewer.Native.x86.v8-xfa

 调用：

 List<string>listFile=   pdfHelper.PdfToImagePdfViewer(ofd.FileName);

源码类  pdfHelper

public List<string> PdfToImagePdfViewer(string pdfFilePath)
{
    List<string> result = new List<string>();    string fullFilePath = Path.GetFullPath(pdfFilePath);
    PdfToPic(pdfFilePath, "D:\\", ImageFormat.Png, ref result);
    return result;
}
/// <summary>
/// <param name="filePath">pdf文件路径</param> 
/// <param name="outFilePath">picture输出文件路径</param> 
/// <param name="image">文件格式：Jpeg  （转换后文件格式，如：Jpeg，Png等）</param> 
/// </summary> 
public void PdfToPic(string filePath, string outFilePath, ImageFormat image, ref List<string> list)
{
    var pdf = PdfDocument.Load(filePath);
    var pdfpage = pdf.PageCount;
    var pagesizes = pdf.PageSizes;
    outFilePath = $"{outFilePath}\\{DateTime.Now.ToString("yyyyMMdd-HHmmss")}";
    for (int i = 1; i <= pdfpage; i++)
    {
        Size size = new Size();
        size.Height = (int)pagesizes[(i - 1)].Height;
        size.Width = (int)pagesizes[(i - 1)].Width;
        //可以把".jpg"写成其他形式 RenderPage(filePath, i, size, picPath); 
        string outFile = $"{outFilePath}({i}).{image}";
        RenderPage(filePath, i, size, outFile, image);
        list.Add(outFile);
    }}
/// <summary>
/// 渲染图片
/// </summary>
/// <param name="pdfPath"></param>
/// <param name="pageNumber"></param>
/// <param name="size"></param>
/// <param name="outputPath"></param>
/// <param name="mat"></param>
/// <param name="dpi"></param>
private void RenderPage(string pdfPath, int pageNumber, System.Drawing.Size size, string outputPath, ImageFormat mat, int dpi = 300)
{
    using (var document = PdfDocument.Load(pdfPath))
    using (var stream = new FileStream(outputPath, FileMode.Create))
    using (var image = GetPageImage(pageNumber, size, document, dpi))
        image.Save(stream, mat);
}
/// <summary>
/// 根据页数转换图片
/// </summary>
/// <param name="pageNumber"></param>
/// <param name="size"></param>
/// <param name="document"></param>
/// <param name="dpi"></param>
/// <returns></returns>
private static System.Drawing.Image GetPageImage(int pageNumber, Size size, PdfDocument document, int dpi)
{
    return document.Render(pageNumber - 1, size.Width, size.Height, dpi, dpi, PdfRenderFlags.CorrectFromDpi);
}public bool ImageToPdf(List<string> ImageList, string pdfFileName)
{      iTextSharp.text.Document document = new iTextSharp.text.Document(iTextSharp.text.PageSize.A4, 25, 25, 25, 25);

        try
        {
            iTextSharp.text.pdf.PdfWriter.GetInstance(document, new FileStream(pdfFileName, FileMode.Create, FileAccess.ReadWrite));
            document.Open();
            iTextSharp.text.Image image;
            foreach (var item in ImageList)
            {
                if (String.IsNullOrEmpty(item)) break;
                image = iTextSharp.text.Image.GetInstance(item);
                if (image.Height > iTextSharp.text.PageSize.A4.Height - 25)
                {
                    image.ScaleToFit(iTextSharp.text.PageSize.A4.Width - 25, iTextSharp.text.PageSize.A4.Height - 25);
                }
                else if (image.Width > iTextSharp.text.PageSize.A4.Width - 25)
                {
                    image.ScaleToFit(iTextSharp.text.PageSize.A4.Width - 25, iTextSharp.text.PageSize.A4.Height - 25);
                }
                image.Alignment = iTextSharp.text.Image.ALIGN_MIDDLE;
                document.NewPage();
                document.Add(image);
            }
            document.Close();
            return true;
        }
        catch (Exception ex)
        {
            Console.WriteLine("转换失败，原因：" + ex.Message);
        }    return false;
}