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