• pdf 使用心得


    最近公司要用一个pdf生成相关的功能,借此机会把生成pdf的开源工具,大部分是熟悉了一下,希望对新做的人能有所帮助,
    Itextsharp 这个是用的最多的,也是生成pdf文件应该是最快的,也是最容易上手的工具,仅仅几行的代码就生成一个标准的
    pdf文件
                Document document = new Document();
                PdfWriter wirte = PdfWriter.GetInstance(document, new FileStream("Chap0101c.pdf", FileMode.Create));

                document.Open();
                Image img = Image.GetInstance(@"http://www.google.cn/intl/zh-CN/images/logo_cn.gif");
                img.Alt = "fsfsfsfsfsfsfsF";
                document.Add(img);
                document.Close();
    当然要加上itextsharp的 dll 了,不过这个source 的sample 都是比较旧的,好多功能都和例子中的有很大的出入的。具体的功能
    可以参照例子,还有就是 http://www.cnblogs.com/hardrock/category/53568.html,是博客园的一个朋友的,我就不细说了
    pdfbox 是java的开源的一个版本,不过有.net的版本的dll 可以用的,不过用的时候大部分的东西还是java的比若FileInputStream
    就是java.io命名控件的东东,不过用起来也是蛮方便的,很容易就找到了pdf中的一些pdfobject对象,比如 image text 等等的功能
    还是比较有用的
          PDDocument doc = PDDocument.load(readFile);

                PDDocument pdf = null;
                FileInputStream pdfStream = null;
                try
                {
                    pdfStream = new FileInputStream(readFile);
                    PDFParser pdfParser = new PDFParser(pdfStream);
                    pdfParser.parse(); // 分析
                    pdf = pdfParser.getPDDocument();
                    int imageCounter = 1;
                    List pages = pdf.getDocumentCatalog().getAllPages();
                    Iterator iter = pages.iterator();
                    while (iter.hasNext())
                    {
                        PDPage page = (PDPage)iter.next();
                        PDResources resources = page.getResources();
                        Map images = resources.getImages();
                       if (images != null)
                        {
                            Iterator imageIter = images.keySet().iterator();
                            while (imageIter.hasNext())
                            {
                                string key = (string)imageIter.next();
                                PDXObjectImage image = (PDXObjectImage)images.get(key);
                                string fname = key+"." +image.getSuffix ();
                             
                            }
                        }
                    }
                }
                catch (java.lang.Exception ex)
                {
                    Console.WriteLine(ex.getMessage());
                }
                finally
                {
                    if (pdfStream != null)
                    {
                        pdfStream.close();
                    }
                }
              
    如果对pdf的结构比较熟悉的话,可以用他来,应该是比较容易的就能满足你的要求
    最后我介绍一下 PdfSharp
    这个是我用来最后能满足我们要求的一个dll
    下面的方法是获得pdf文件中的text
     public string ExtractContentForSummary()
            {
                string result = string.Empty;
                try
                {
                    document = PdfReader.Open(_fileName);

                    foreach (PdfPage page in document.Pages)
                    {
                        CSequence seq = ContentReader.ReadContent(page);
                        for (int idx = 0; idx < seq.Count; idx++)
                        {
                            CObject obj = seq[idx];
                            COperator op = obj as COperator;
                            if (op != null && op.OpCode.OpCodeName == OpCodeName.Tj)
                            {
                                if (op.Operands.Count == 1)
                                {

                                    CString s = op.Operands[0] as CString;
                                    result += s;
                                }
                            }
                        }

                    }
                    document.Close();
                    return result;
                }
                catch (PdfSharpException ex)
                {
                    throw ex;
                }
                finally
                {
                    document.Close();
                }
            }
     获得所有的image对象
     public PdfDictionary[] GetAllImageFromPDF(ref PdfDocument document)
            {

                List<PdfDictionary> list = new List<PdfDictionary>();
                // Iterate pages
                foreach (PdfPage page in document.Pages)
                {
                    // Get resources dictionary
                    PdfDictionary resources = page.Elements.GetDictionary("/Resources");
                    if (resources != null)
                    {
                        // Get external objects dictionary
                        PdfDictionary xObjects = resources.Elements.GetDictionary("/XObject");
                        if (xObjects != null)
                        {
                            PdfItem[] items = xObjects.Elements.Values;
                            // Iterate references to external objects
                            foreach (PdfItem item in items)
                            {
                                PdfReference reference = item as PdfReference;
                                if (reference != null)
                                {
                                    PdfDictionary xObject = reference.Value as PdfDictionary;
                                    // Is external object an image?
                                    if (xObject != null && xObject.Elements.GetString("/Subtype") == "/Image")
                                    {
                                        list.Add(xObject);

                                    }
                                }
                            }
                        }
                    }
                }
                return list.ToArray();
            }
    替换图片的
      public void PlaceSignature(PositionInfo posInfo, string pictureFile)
            {
                try
                {
                    document = PdfReader.Open(_fileName);
                    List<PdfDictionary> list = new List<PdfDictionary>();
                    // Iterate pages
                    foreach (PdfPage page in document.Pages)
                    {
                        // Get resources dictionary
                        PdfDictionary resources = page.Elements.GetDictionary("/Resources");
                        if (resources != null)
                        {
                            // Get external objects dictionary
                            PdfDictionary xObjects = resources.Elements.GetDictionary("/XObject");
                            if (xObjects != null)
                            {
                                PdfItem[] items = xObjects.Elements.Values;
                                // Iterate references to external objects
                                foreach (PdfItem item in items)
                                {
                                    PdfReference reference = item as PdfReference;
                                    if (reference != null)
                                    {
                                        PdfDictionary xObject = reference.Value as PdfDictionary;
                                        // Is external object an image?
                                        if (xObject != null && xObject.Elements.GetString("/Subtype") == "/Image")
                                        {
                                            string position = GlobalFunction.GetCommentFromJPG(xObject.Stream.Value);
                                            if (position == posInfo.Name)
                                            {
                                                XImage ximage = XImage.FromFile(pictureFile);
                                                PdfImage pdfimage = new PdfImage(document, ximage);

                                                xObject.Stream.Value = pdfimage.Stream.Value;
                                                document.Save(FileName);
                                                ximage.Dispose();
                                                break;
                                            }
                                        }
                                    }
                                }
                            }
                        }
                    }
                }
                catch (PdfSharpException ex)
                {
                    throw ex;
                }
                finally
                {
                    document.Close();
                }
            }
    以上就是大部分人用到的用途,正好把我用到的方法共享出来,希望对别人有用,也欢迎有好的方法可以和我交流
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  • 原文地址:https://www.cnblogs.com/jfliuyun/p/1018381.html
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