如何在并行foreach循环中使用IText7的CreateTiff方法？

Question

我写了一些代码，通过iText7将tiff文件转换成pdf文件。但是当我启动它时，它在方法image.imageDataFactory.createTIFF上有死锁。如果将parallel.foreach替换为foreach则所有工作都正确。我做错了什么？

void Run(List<string> tiffsPaths)
{
   Parallel.ForEach(tiffsPaths, ConvertTiffToPdf)
}

void ConvertTiffToPdf(string tiffPath)
{
   var fileName = Path.GetFileNameWithoutExtension(tiffPath);
   var pdfPath = Path.Combine(this.outputPicPath, fileName + ".pdf");

   var pdfWriter = new PdfWriter(pdfPath);
   var document = new PdfDocument(pdfWriter);
   var workDir = Path.GetDirectoryName(SourceFile) ?? string.Empty;
   var pageNum = 1;

   var tiffImage = Image.ImageDataFactory.CreateTiff(new Uri(tiffPath), true, pageNum, true);
   var tiffPageSize = new Geom.Rectangle(tiffImage.GetWidth(), 
   tiffImage.GetHeight());
   var newPage = document.AddNewPage(new Geom.PageSize(tiffPageSize));
   var canvas = new PdfCanvas(newPage);
   canvas.AddImage(tiffImage, tiffPageSize, false);

   document.Close();
   pdfWriter.Close();
}

UPD在itext.io.source.RandomAccessSourceFactory类的方法Public IRandomAccessSource CreateSource（Uri url)中找到了IText7源代码中发生死锁的地方。这里有这部分代码：

WebRequest wr = WebRequest.Create(url);
wr.Credentials = CredentialCache.DefaultCredentials;
Stream isp = wr.GetResponse().GetResponseStream();

Answer 1

将var tiffImage=image.imageDataActory.CreateTIFF（新Uri（tiffPath）,true,pageNum,true）；替换为var tiffImage=image.imageDataActory.CreateTIFF（file.ReadAllBytes（path）,true,pageNum,true）；并且所有操作都很好