是否有一个开放源代码库可以帮助我阅读/解析.Net / C＃中的PDF文档？

解决方案

回答

我们可以查看以下内容：
http://www.codeproject.com/KB/showcase/pdfrasterizer.aspx
它不是完全免费的，但看起来非常不错。

亚历克斯

回答

PDFClown可能会有所帮助，但我不建议将其用于大量使用的应用程序。

回答

也有LibHaru

http://libharu.org/wiki/Main_Page

回答

iText是我所知道的最好的库。最初是用Java编写的，还有一个.NET端口。

参见http://www.ujihara.jp/iTextdotNET/en/

回答

http://www.c-sharpcorner.com/UploadFile/psingh/PDFFileGenerator12062005235236PM/PDFFileGenerator.aspx是开源的，可能对我们来说是一个很好的起点。

回答

过去，我曾使用ITextSharp来操纵/拆分和重新整理PDF文档-这非常简单，而且也是开源的。

回答

iTextSharp是最好的选择。用它为lucene.Net制作了一个蜘蛛，这样它就可以抓取PDF。

using System;
using System.IO;
using iTextSharp.text.pdf;
using System.Text.RegularExpressions;

namespace Spider.Utils
{
    /// <summary>
    /// Parses a PDF file and extracts the text from it.
    /// </summary>
    public class PDFParser
    {
        /// BT = Beginning of a text object operator 
        /// ET = End of a text object operator
        /// Td move to the start of next line
        ///  5 Ts = superscript
        /// -5 Ts = subscript

        #region Fields

        #region _numberOfCharsToKeep
        /// <summary>
        /// The number of characters to keep, when extracting text.
        /// </summary>
        private static int _numberOfCharsToKeep = 15;
        #endregion

        #endregion

        #region ExtractText
        /// <summary>
        /// Extracts a text from a PDF file.
        /// </summary>
        /// <param name="inFileName">the full path to the pdf file.</param>
        /// <param name="outFileName">the output file name.</param>
        /// <returns>the extracted text</returns>
        public bool ExtractText(string inFileName, string outFileName)
        {
            StreamWriter outFile = null;
            try
            {
                // Create a reader for the given PDF file
                PdfReader reader = new PdfReader(inFileName);
                //outFile = File.CreateText(outFileName);
                outFile = new StreamWriter(outFileName, false, System.Text.Encoding.UTF8);

                Console.Write("Processing: ");

                int totalLen = 68;
                float charUnit = ((float)totalLen) / (float)reader.NumberOfPages;
                int totalWritten = 0;
                float curUnit = 0;

                for (int page = 1; page <= reader.NumberOfPages; page++)
                {
                    outFile.Write(ExtractTextFromPDFBytes(reader.GetPageContent(page)) + " ");

                    // Write the progress.
                    if (charUnit >= 1.0f)
                    {
                        for (int i = 0; i < (int)charUnit; i++)
                        {
                            Console.Write("#");
                            totalWritten++;
                        }
                    }
                    else
                    {
                        curUnit += charUnit;
                        if (curUnit >= 1.0f)
                        {
                            for (int i = 0; i < (int)curUnit; i++)
                            {
                                Console.Write("#");
                                totalWritten++;
                            }
                            curUnit = 0;
                        }

                    }
                }

                if (totalWritten < totalLen)
                {
                    for (int i = 0; i < (totalLen - totalWritten); i++)
                    {
                        Console.Write("#");
                    }
                }
                return true;
            }
            catch
            {
                return false;
            }
            finally
            {
                if (outFile != null) outFile.Close();
            }
        }
        #endregion

        #region ExtractTextFromPDFBytes
        /// <summary>
        /// This method processes an uncompressed Adobe (text) object 
        /// and extracts text.
        /// </summary>
        /// <param name="input">uncompressed</param>
        /// <returns></returns>
        public string ExtractTextFromPDFBytes(byte[] input)
        {
            if (input == null || input.Length == 0) return "";

            try
            {
                string resultString = "";

                // Flag showing if we are we currently inside a text object
                bool inTextObject = false;

                // Flag showing if the next character is literal 
                // e.g. '\' to get a '\' character or '\(' to get '('
                bool nextLiteral = false;

                // () Bracket nesting level. Text appears inside ()
                int bracketDepth = 0;

                // Keep previous chars to get extract numbers etc.:
                char[] previousCharacters = new char[_numberOfCharsToKeep];
                for (int j = 0; j < _numberOfCharsToKeep; j++) previousCharacters[j] = ' ';

                for (int i = 0; i < input.Length; i++)
                {
                    char c = (char)input[i];
                    if (input[i] == 213)
                        c = "'".ToCharArray()[0];

                    if (inTextObject)
                    {
                        // Position the text
                        if (bracketDepth == 0)
                        {
                            if (CheckToken(new string[] { "TD", "Td" }, previousCharacters))
                            {
                                resultString += "\n\r";
                            }
                            else
                            {
                                if (CheckToken(new string[] { "'", "T*", "\"" }, previousCharacters))
                                {
                                    resultString += "\n";
                                }
                                else
                                {
                                    if (CheckToken(new string[] { "Tj" }, previousCharacters))
                                    {
                                        resultString += " ";
                                    }
                                }
                            }
                        }

                        // End of a text object, also go to a new line.
                        if (bracketDepth == 0 &&
                            CheckToken(new string[] { "ET" }, previousCharacters))
                        {

                            inTextObject = false;
                            resultString += " ";
                        }
                        else
                        {
                            // Start outputting text
                            if ((c == '(') && (bracketDepth == 0) && (!nextLiteral))
                            {
                                bracketDepth = 1;
                            }
                            else
                            {
                                // Stop outputting text
                                if ((c == ')') && (bracketDepth == 1) && (!nextLiteral))
                                {
                                    bracketDepth = 0;
                                }
                                else
                                {
                                    // Just a normal text character:
                                    if (bracketDepth == 1)
                                    {
                                        // Only print out next character no matter what. 
                                        // Do not interpret.
                                        if (c == '\' && !nextLiteral)
                                        {
                                            resultString += c.ToString();
                                            nextLiteral = true;
                                        }
                                        else
                                        {
                                            if (((c >= ' ') && (c <= '~')) ||
                                                ((c >= 128) && (c < 255)))
                                            {
                                                resultString += c.ToString();
                                            }

                                            nextLiteral = false;
                                        }
                                    }
                                }
                            }
                        }
                    }

                    // Store the recent characters for 
                    // when we have to go back for a checking
                    for (int j = 0; j < _numberOfCharsToKeep - 1; j++)
                    {
                        previousCharacters[j] = previousCharacters[j + 1];
                    }
                    previousCharacters[_numberOfCharsToKeep - 1] = c;

                    // Start of a text object
                    if (!inTextObject && CheckToken(new string[] { "BT" }, previousCharacters))
                    {
                        inTextObject = true;
                    }
                }

                return CleanupContent(resultString);
            }
            catch
            {
                return "";
            }
        }

        private string CleanupContent(string text)
        {
            string[] patterns = { @"\\(", @"\\)", @"\226", @"\222", @"\223", @"\224", @"\340", @"\342", @"\344", @"\300", @"\302", @"\304", @"\351", @"\350", @"\352", @"\353", @"\311", @"\310", @"\312", @"\313", @"\362", @"\364", @"\366", @"\322", @"\324", @"\326", @"\354", @"\356", @"\357", @"\314", @"\316", @"\317", @"\347", @"\307", @"\371", @"\373", @"\374", @"\331", @"\333", @"\334", @"\256", @"\231", @"\253", @"\273", @"\251", @"\221"};
            string[] replace = {   "(",     ")",      "-",     "'",      "\"",      "\"",    "à",      "a",      "?",      "à",      "?",      "?",      "é",      "è",      "ê",      "?",      "é",      "è",      "ê",      "?",      "ò",      "?",      "?",      "ò",      "?",      "?",      "ì",      "?",      "?",      "ì",      "?",      "?",      "?",      "?",      "ù",      "?",      "ü",      "ù",      "?",      "ü",      "?",      "?",      "?",      "?",      "?",      "'" };

            for (int i = 0; i < patterns.Length; i++)
            {
                string regExPattern = patterns[i];
                Regex regex = new Regex(regExPattern, RegexOptions.IgnoreCase);
                text = regex.Replace(text, replace[i]);
            }

            return text;
        }

        #endregion

        #region CheckToken
        /// <summary>
        /// Check if a certain 2 character token just came along (e.g. BT)
        /// </summary>
        /// <param name="tokens">the searched token</param>
        /// <param name="recent">the recent character array</param>
        /// <returns></returns>
        private bool CheckToken(string[] tokens, char[] recent)
        {
            foreach (string token in tokens)
            {
                if ((recent[_numberOfCharsToKeep - 3] == token[0]) &&
                    (recent[_numberOfCharsToKeep - 2] == token[1]) &&
                    ((recent[_numberOfCharsToKeep - 1] == ' ') ||
                    (recent[_numberOfCharsToKeep - 1] == 0x0d) ||
                    (recent[_numberOfCharsToKeep - 1] == 0x0a)) &&
                    ((recent[_numberOfCharsToKeep - 4] == ' ') ||
                    (recent[_numberOfCharsToKeep - 4] == 0x0d) ||
                    (recent[_numberOfCharsToKeep - 4] == 0x0a))
                    )
                {
                    return true;
                }
            }
            return false;
        }
        #endregion
    }
}

回答

aspose pdf效果很好。再说一遍，你必须付钱