替换PDF中的特定文档 [英] Replace Specific Document in PDF

问题描述

包括:

using Ghostscript.NET;
using Ghostscript.NET.Processor;
using Ghostscript.NET.Rasterizer;

现在，我正在使用Ghostscript.Net将多个单个PDF合并为一个文档:

Right now, I am using Ghostscript.Net to merge several single PDFs into a single document:

/// <summary>
/// Ghostscripts the file specified in parameter 1 as a PDF to the file specified in parameter 2
/// </summary>
/// <param name="fileNames">String[]. Array of Full Paths to a file to convert to a single PDF</param>
/// <param name="outputPath">String. Full Path to where Ghostscript will write the PDF</param>
public static void GhostscriptNetJoin(String[] fileNames, String outputPath)
{
    var sb = new StringBuilder();
    foreach (var fileName in fileNames)
    {
        var source = (fileName.IndexOf(' ') == -1) ? fileName : String.Format("\"{0}\"", fileName);
        sb.Append(source + " ");
    }
    var output_file = (outputPath.IndexOf(' ') == -1) ? outputPath : String.Format("\"{0}\"", outputPath);
    var gsArgs = new List<String>();
    gsArgs.Add("-empty"); // first argument is ignored. REF: http://stackoverflow.com/q/25202577/153923
    gsArgs.Add("-dBATCH");
    gsArgs.Add("-q");
    gsArgs.Add("-dNOPAUSE");
    gsArgs.Add("-dNOPROMPT");
    gsArgs.Add("-sDEVICE=pdfwrite");
    gsArgs.Add("-dPDFSETTINGS=/prepress");
    gsArgs.Add(String.Format(@"-sOutputFile={0}", output_file));
    gsArgs.Add(sb.ToString());
    var version = GhostscriptVersionInfo.GetLastInstalledVersion();
    using (var processor = new GhostscriptProcessor(version, false))
    {
        processor.Process(gsArgs.ToArray());
    }
}

我稍后如何返回 REPLACE或UPDATE 页N?

我已经制定了具有计划的例程，但是目前我不知道如何完成该计划.我可以提供arg值还是应该使用其他工具?

I have stubbed out a routine that has my plan, but at this time I do not know how to complete it. Can I supply arg values or is there a different tool I should be using?

/// <summary>
/// Replace Specific Document from source PDF file
/// </summary>
/// <param name="source">String. Full path to the multi-page PDF</param>
/// <param name="documentN">String. Full path to the document to insert</param>
/// <param name="indexN">int. Page Index where the new document should be inserted</param>
public static void GhostscriptNetReplace(String source, String documentN, int indexN)
{
    var list = new List<String>();
    var version = GhostscriptVersionInfo.GetLastInstalledVersion();
    using (var processor = new GhostscriptProcessor(version, false))
    {
        var gsArgs = new List<String>();
        // what arguments are needed?
        throw new NotImplementedException("I don't know how to code for this yet.");
        processor.Process(gsArgs.ToArray());
    }
    list.RemoveAt(indexN);
    list.Insert(indexN, documentN);
    var sb = new StringBuilder();
    foreach (var fileName in list)
    {
        var fmtSource = (fileName.IndexOf(' ') == -1) ? fileName : String.Format("\"{0}\"", fileName);
        sb.Append(fmtSource + " ");
    }
    var output_file = (source.IndexOf(' ') == -1) ? source : String.Format("\"{0}\"", source);
    using (var processor = new GhostscriptProcessor(version, false))
    {
        var gsArgs = new List<String>();
        gsArgs.Add("-empty"); // first argument is ignored. REF: http://stackoverflow.com/q/25202577/153923
        gsArgs.Add("-dBATCH");
        gsArgs.Add("-q");
        gsArgs.Add("-dNOPAUSE");
        gsArgs.Add("-dNOPROMPT");
        gsArgs.Add("-sDEVICE=pdfwrite");
        gsArgs.Add("-dPDFSETTINGS=/prepress");
        gsArgs.Add(String.Format(@"-sOutputFile={0}", output_file));
        gsArgs.Add(sb.ToString());
        processor.Process(gsArgs.ToArray());
    }
}

推荐答案

我将根据我在baaron的帖子中所读内容添加答案:

I'm going to add an answer based on what I read in baaron's post here:

无需使用特定的C#库即可将PDF转换为JPG/图像

我修改了他的代码，我认为它将满足我的需求.但是，就像KenS在上面的评论中发布的那样，每次运行都会继续质量下降.

I modified his code, and I think it will satisfy my needs. Like KenS posted in a comment above, though, this will continue to lose quality each time it is run.

/// <summary>
/// Replaces document at provided index with new document.
/// Use with Caution! If you continuously cycle using the output as the input,
/// then you run repeated risks of information or quality loss.
/// </summary>
/// <param name="source">String. Full File Path to Source</param>
/// <param name="documentN">String. Full File Path to new document</param>
/// <param name="indexN">int. Index where file needs to go</param>
public static void GhostscriptNetReplace(String source, String documentN, int indexN)
{
    var list = new List<String>();
    var version = GhostscriptVersionInfo.GetLastInstalledVersion();
    var fullPath = Path.GetFullPath(source);
    int index = -1;
    using (var rasterizer = new Ghostscript.NET.Rasterizer.GhostscriptRasterizer())
    {
        rasterizer.Open(source, version, false);
        for (index = 0; index < rasterizer.PageCount; index++)
        {
            if (index != indexN)
            {
                var extracted = Path.Combine(fullPath, String.Format("~1_{0}.jpg", index));
                if (File.Exists(extracted))
                {
                    File.Delete(extracted);
                }
                var img = rasterizer.GetPage(300, 300, index);
                img.Save(extracted, ImageFormat.Jpeg);
                list.Add(extracted);
            } else
            {
                list.Add(documentN);
            }
        }
        if (index == indexN) // occurs if adding a page to the end
        {
            list.Add(documentN);
        }
    }
    var output_file = (source.IndexOf(' ') == -1) ? source : String.Format("\"{0}\"", source);
    using (var processor = new GhostscriptProcessor(version, false))
    {
        var gsArgs = new List<String>();
        gsArgs.Add("-empty"); // first argument is ignored. REF: https://stackoverflow.com/q/25202577/153923
        gsArgs.Add("-dBATCH");
        gsArgs.Add("-q");
        gsArgs.Add("-dNOPAUSE");
        gsArgs.Add("-dNOPROMPT");
        gsArgs.Add("-sDEVICE=pdfwrite");
        gsArgs.Add("-dPDFSETTINGS=/prepress");
        gsArgs.Add(String.Format(@"-sOutputFile={0}", output_file));
        foreach (var fileName in list)
        {
            var source = (fileName.IndexOf(' ') == -1) ? fileName : String.Format("\"{0}\"", fileName);
            gsArgs.Add(source);
        }
        processor.Process(gsArgs.ToArray());
    }
    foreach (var fileName in list) // delete the temp files
    {
        File.Delete(fileName);
    }
}

工作已决定暂时推迟，因为他们还没有准备冒失去信息质量的风险.

Work has decided to put this off for now because they are not ready to risk losing information quality.

然后，此代码未经测试就被放在那里.

This code, then, is put out there as untested.

从理论上讲，它应该起作用.

In theory, it should work.

如果有帮助，请告诉我.如果没有人看我，我讨厌跟进我自己问题的答案.

If it helps, please let me know. I hate following up with answers to my own questions if no one ever looks at it.

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