iTextSharp创建的PDF仍在使用中

Question

如果我使用给定的源代码创建pdf，则会出现无法打开pdf文档的问题，例如“ adobe-acrobat”，因为它表示该文件仍在被其他进程使用。我在释放锁的代码中缺少什么？

var a = Guid.NewGuid();

Document pdfDoc = new Document(PageSize.A4, 10f, 10f, 10f, 0f);

PdfWriter writer2 = PdfWriter.GetInstance(pdfDoc, new FileStream(a.ToString()+".pdf", FileMode.Create));
writer2.SetFullCompression();
writer2.CloseStream = true;

iTextSharp.text.Image img = iTextSharp.text.Image.GetInstance(AppContext.BaseDirectory + "Ehrungsantrag.png");
img.SetAbsolutePosition(0, 0);
img.ScaleAbsoluteHeight(pdfDoc.PageSize.Height);
img.ScaleAbsoluteWidth(pdfDoc.PageSize.Width);
pdfDoc.Open();
pdfDoc.NewPage();
pdfDoc.Add(img);

pdfDoc.Close();
writer2.Close();

Answer 1

Answer 2

Document pdfDoc = null;
PdfWriter writer2 = null;
System.IO.FileStream fs = null;

try
{
   var a = Guid.NewGuid();
   pdfDoc = new Document(PageSize.A4, 10f, 10f, 10f, 0f);

   fs =  new FileStream(a.ToString()+".pdf", FileMode.Create);
   writer2 = PdfWriter.GetInstance(pdfDoc, fs);
   writer2.SetFullCompression();
   writer2.CloseStream = true;

   iTextSharp.text.Image img = iTextSharp.text.Image.GetInstance(AppContext.BaseDirectory + "Ehrungsantrag.png");
   img.SetAbsolutePosition(0, 0);
   img.ScaleAbsoluteHeight(pdfDoc.PageSize.Height);
   img.ScaleAbsoluteWidth(pdfDoc.PageSize.Width);

   pdfDoc.Open();
   pdfDoc.NewPage();
   pdfDoc.Add(img);
}
catch (iTextSharp.text.DocumentException dex) 
{
   // special error handling
}
catch (Exception ex) 
{
   // generic error handling
}
finally
{
        pdfDoc.Close();
        pdfDoc = null;

        writer2.Close(); 

       // Always close open filehandles explicity  
       fs.Close(); 
}