C# PDF to image

最新推荐文章于 2024-09-23 10:50:49 发布

转载最新推荐文章于 2024-09-23 10:50:49 发布 · 2k 阅读

文章标签：

#c# #string #subprocess #image

本文介绍如何利用Ghostscript这一免费工具生成PDF文件的缩略图。通过C#代码示例展示了批量处理PDF页面并转换为JPEG格式图片的方法。

可以使用Ghostscript ，免费的，我们一直在用。下载地址 http://sourceforge.net/project/showfiles.php?group_id=1897&package_id=108733

C# code


  public IList<string> GenerateThumbnailImage(string InputFile, bool deletePDF, string filename)
        {
            return GenerateImage(InputFile, deletePDF, filename, "-dSAFER -dBATCH -dNOPAUSE -r150 -sDEVICE=jpeg -dGraphicsAlphaBits=4");
        }



        private IList<string> GenerateImage(string InputFile, bool deletePDF, string filename,string Arguments)
        {
             IList<string> result = new List<string>();
            PDFLibrary myPDFLibrary = new PDFLibrary();
            int PDFPageCount = myPDFLibrary.GetPageCount(InputFile);
            if (PDFPageCount==0)
            {
                return result;
            }

            string OutputFile = filename;

            string ExtOut = Path.GetExtension(OutputFile);
            string partOut = OutputFile.Remove(OutputFile.Length - ExtOut.Length, ExtOut.Length);

            if (PDFPageCount == 1)
            {
                OutputFile=partOut+ ".jpg";
                result.Add(OutputFile);
                if (File.Exists(OutputFile))
                {
                    File.Delete(OutputFile);
                }
            }

            else
            {
                for (int i = 0; i < PDFPageCount; i++)
                {
                    string eachFileName = partOut + (i + 1).ToString() + ".jpg";
                    result.Add(eachFileName);
                    if (File.Exists(eachFileName))
                    {
                        File.Delete(eachFileName);
                    }
                }

                OutputFile = OutputFile.Remove(OutputFile.Length - ExtOut.Length, ExtOut.Length);
                OutputFile += "%d.jpg";
            }
           

            
            ProcessStartInfo info = new ProcessStartInfo();
            info.CreateNoWindow = true;
            info.WindowStyle = ProcessWindowStyle.Hidden;
            info.WorkingDirectory = System.Configuration.ConfigurationManager.AppSettings["GhostScriptView"];
            info.Arguments =Arguments+ @" -sOutputFile=" + OutputFile + "  " + InputFile;
            info.FileName = @"gswin32c.exe";
            Process subProcess = new Process();
            subProcess.StartInfo = info;
            subProcess.Start();
            subProcess.WaitForExit(int.MaxValue);
            if (deletePDF)
            {
                System.IO.File.Delete(InputFile);
            }
            return result;
            
        }