michael_wp原创：用.net实现zip----4

//ZipLib.cs
using System;
using System.IO;
using System.Text;
using System.Runtime.InteropServices;

namespace OrganicBit.Zip {

    /// <summary>Support methods for uncompressing zip files.</summary>
    /// <remarks>
    ///   <para>This unzip package allow extract file from .ZIP file, compatible with PKZip 2.04g WinZip, InfoZip tools and compatible.</para>
    ///   <para>Encryption and multi volume ZipFile (span) are not supported.  Old compressions used by old PKZip 1.x are not supported.</para>
    ///   <para>Copyright (C) 1998 Gilles Vollant.  http://www.winimage.com/zLibDll/unzip.htm</para>
    ///   <para>C# wrapper by Gerry Shaw (gerry_shaw@yahoo.com).  http://www.organicbit.com/zip/</para>
    /// </remarks>
    internal sealed class ZipLib {

        // prevent instances of this class from being constructed
        private ZipLib() {}

        /*
            Create a zipfile.
            pathname contain on Windows NT a filename like "c:\\zlib\\zlib111.zip" or on an Unix computer "zlib/zlib111.zip".
            if the file pathname exist and append=1, the zip will be created at the end of the file. (useful if the file contain a self extractor code)
            If the zipfile cannot be opened, the return value is NULL.
            Else, the return value is a zipFile Handle, usable with other function of this zip package.
        */
        /// <summary>Create a zip file.</summary>
        [DllImport("zlib.dll", ExactSpelling=true, CharSet=CharSet.Ansi)]
        public static extern IntPtr zipOpen(string fileName, int append);

        /*
            Open a file in the ZIP for writing.
            filename : the filename in zip (if NULL, @#-@# without quote will be used
            *zipfi contain supplemental information
            if extrafield_local!=NULL and size_extrafield_local>0, extrafield_local contains the extrafield data the the local header
            if extrafield_global!=NULL and size_extrafield_global>0, extrafield_global contains the extrafield data the the local header
            if comment != NULL, comment contain the comment string
            method contain the compression method (0 for store, Z_DEFLATED for deflate)
            level contain the level of compression (can be Z_DEFAULT_COMPRESSION)
        */
        /// <summary>Open a new zip entry for writing.</summary>
        [DllImport("zlib.dll", ExactSpelling=true, CharSet=CharSet.Ansi)]
        unsafe public static extern int zipOpenNewFileInZip(IntPtr handle,
            string entryName,
            ZipFileEntryInfo* entryInfoPtr,
            byte[] extraField,
            uint extraFieldLength,
            byte[] extraFieldGlobal,
            uint extraFieldGlobalLength,
            string comment,
            int method,
            int level);


        /// <summary>Write data to the zip file.</summary>
        [DllImport("zlib.dll")]
        public static extern int zipWriteInFileInZip(IntPtr handle, byte[] buffer, uint count);

        /// <summary>Close the current entry in the zip file.</summary>
        [DllImport("zlib.dll")]
        public static extern int zipCloseFileInZip(IntPtr handle);

        /// <summary>Close the zip file.</summary>
        [DllImport("zlib.dll", ExactSpelling=true, CharSet=CharSet.Ansi)]
        public static extern int zipClose(IntPtr handle, string comment);


        /// <summary>Opens a zip file for reading.</summary>
        /// <param name="fileName">The name of the zip to open.  At this time only file names with ANSI (8 bit) characters are supported.</param>
        /// <returns>
        ///   <para>A handle usable with other functions of the ZipLib class.</para>
        ///   <para>Otherwise IntPtr.Zero if the zip file could not e opened (file doen not exist or is not valid).</para>
        /// </returns>
        [DllImport("zlib.dll", ExactSpelling=true, CharSet=CharSet.Ansi)]
        public static extern IntPtr unzOpen(string fileName);

        /// <summary>Closes a zip file opened with unzipOpen.</summary>
        /// <param name="handle">The zip file handle opened by <see cref="unzOpenCurrentFile"/>.</param>
        /// <remarks>If there are files inside the zip file opened with <see cref="unzOpenCurrentFile"/> these files must be closed with <see cref="unzCloseCurrentFile"/> before call <c>unzClose</c>.</remarks>
        /// <returns>
        ///   <para>Zero if there was no error.</para>
        ///   <para>Otherwise a value less than zero.  See <see cref="ErrorCode"/> for the specific reason.</para>
        /// </returns>
        [DllImport("zlib.dll")]
        public static extern int unzClose(IntPtr handle);

        /// <summary>Get global information about the zip file.</summary>
        /// <param name="handle">The zip file handle opened by <see cref="unzOpenCurrentFile"/>.</param>
        /// <param name="globalInfoPtr">An address of a <see cref="ZipFileInfo"/> struct to hold the information.  No preparation of the structure is needed.</param>
        /// <returns>
        ///   <para>Zero if there was no error.</para>
        ///   <para>Otherwise a value less than zero.  See <see cref="ErrorCode"/> for the specific reason.</para>
        /// </returns>
        [DllImport("zlib.dll")]
        public unsafe static extern int unzGetGlobalInfo(IntPtr handle, ZipFileInfo* globalInfoPtr);

        /// <summary>Get the comment associated with the entire zip file.</summary>
        /// <param name="handle">The zip file handle opened by <see cref="unzOpenCurrentFile"/></param>
        /// <param name="commentBuffer">The buffer to hold the comment.</param>
        /// <param name="commentBufferLength">The length of the buffer in bytes (8 bit characters).</param>
        /// <returns>
        ///   <para>The number of characters in the comment if there was no error.</para>
        ///   <para>Otherwise a value less than zero.  See <see cref="ErrorCode"/> for the specific reason.</para>
        /// </returns>
        [DllImport("zlib.dll")]
        public static extern int unzGetGlobalComment(IntPtr handle, sbyte[] commentBuffer, uint commentBufferLength);

        /// <summary>Set the current file of the zip file to the first file.</summary>
        /// <param name="handle">The zip file handle opened by <see cref="unzOpenCurrentFile"/>.</param>
        /// <returns>
        ///   <para>Zero if there was no error.</para>
        ///   <para>Otherwise a value less than zero.  See <see cref="ErrorCode"/> for the specific reason.</para>
        /// </returns>
        [DllImport("zlib.dll")]
        public static extern int unzGoToFirstFile(IntPtr handle);

        /// <summary>Set the current file of the zip file to the next file.</summary>
        /// <param name="handle">The zip file handle opened by <see cref="unzOpenCurrentFile"/>.</param>
        /// <returns>
        ///   <para>Zero if there was no error.</para>
        ///   <para>Otherwise <see cref="ErrorCode.EndOfListOfFile"/> if there are no more entries.</para>
        /// </returns>
        [DllImport("zlib.dll")]
        public static extern int unzGoToNextFile(IntPtr handle);

        /// <summary>Try locate the entry in the zip file.</summary>
        /// <param name="handle">The zip file handle opened by <see cref="unzOpenCurrentFile"/>.</param>
        /// <param name="entryName">The name of the entry to look for.</param>
        /// <param name="caseSensitivity">If 0 use the OS default.  If 1 use case sensitivity like strcmp, Unix style.  If 2 do not use case sensitivity like strcmpi, Windows style.</param>
        /// <returns>
        ///   <para>Zero if there was no error.</para>
        ///   <para>Otherwise <see cref="ErrorCode.EndOfListOfFile"/> if there are no more entries.</para>
        /// </returns>
        [DllImport("zlib.dll", ExactSpelling=true, CharSet=CharSet.Ansi)]
        public static extern int unzLocateFile(IntPtr handle, string entryName, int caseSensitivity);

        /// <summary>Get information about the current entry in the zip file.</summary>
        /// <param name="handle">The zip file handle opened by <see cref="unzOpenCurrentFile"/>.</param>
        /// <param name="entryInfoPtr">A ZipEntryInfo struct to hold information about the entry or null.</param>
        /// <param name="entryNameBuffer">An array of sbyte characters to hold the entry name or null.</param>
        /// <param name="entryNameBufferLength">The length of the entryNameBuffer in bytes.</param>
        /// <param name="extraField">An array to hold the extra field data for the entry or null.</param>
        /// <param name="extraFieldLength">The length of the extraField array in bytes.</param>
        /// <param name="commentBuffer">An array of sbyte characters to hold the entry name or null.</param>
        /// <param name="commentBufferLength">The length of theh commentBuffer in bytes.</param>
        /// <remarks>
        ///   <para>If entryInfoPtr is not null the structure will contain information about the current file.</para>
        ///   <para>If entryNameBuffer is not null the name of the entry will be copied into it.</para>
        ///   <para>If extraField is not null the extra field data of the entry will be copied into it.</para>
        ///   <para>If commentBuffer is not null the comment of the entry will be copied into it.</para>
        /// </remarks>
        /// <returns>
        ///   <para>Zero if there was no error.</para>
        ///   <para>Otherwise a value less than zero.  See <see cref="ErrorCode"/> for the specific reason.</para>
        /// </returns>
        [DllImport("zlib.dll", ExactSpelling=true, CharSet=CharSet.Ansi)]
        public unsafe static extern int unzGetCurrentFileInfo(IntPtr handle, ZipEntryInfo* entryInfoPtr,
            sbyte[] entryNameBuffer, uint entryNameBufferLength,
            byte[]  extraField,      uint extraFieldLength,
            sbyte[] commentBuffer,   uint commentBufferLength);

        /// <summary>Open the zip file entry for reading.</summary>
        /// <param name="handle">The zip file handle opened by <see cref="unzOpenCurrentFile"/>.</param>
        /// <returns>
        ///   <para>Zero if there was no error.</para>
        ///   <para>Otherwise a value from <see cref="ErrorCode"/>.</para>
        /// </returns>
        [DllImport("zlib.dll")]
        public static extern int unzOpenCurrentFile(IntPtr handle);

        /// <summary>Close the file entry opened by <see cref="unzOpenCurrentFile"/>.</summary>
        /// <param name="handle">The zip file handle opened by <see cref="unzOpenCurrentFile"/>.</param>
        /// <returns>
        ///   <para>Zero if there was no error.</para>
        ///   <para>CrcError if the file was read but the Crc does not match.</para>
        ///   <para>Otherwise a value from <see cref="ErrorCode"/>.</para>
        /// </returns>
        [DllImport("zlib.dll")]
        public static extern int unzCloseCurrentFile(IntPtr handle);

        /// <summary>Read bytes from the current zip file entry.</summary>
        /// <param name="handle">The zip file handle opened by <see cref="unzOpenCurrentFile"/>.</param>
        /// <param name="buffer">Buffer to store the uncompressed data into.</param>
        /// <param name="count">Number of bytes to write from <paramref name="buffer"/>.</param>
        /// <returns>
        ///   <para>The number of byte copied if somes bytes are copied.</para>
        ///   <para>Zero if the end of file was reached.</para>
        ///   <para>Less than zero with error code if there is an error.  See <see cref="ErrorCode"/> for a list of possible error codes.</para>
        /// </returns>
        [DllImport("zlib.dll")]
        public static extern int unzReadCurrentFile(IntPtr handle, byte[] buffer, uint count);

        /// <summary>Give the current position in uncompressed data of the zip file entry currently opened.</summary>
        /// <param name="handle">The zip file handle opened by <see cref="unzOpenCurrentFile"/>.</param>
        /// <returns>The number of bytes into the uncompressed data read so far.</returns>
        [DllImport("zlib.dll")]
        public static extern long unztell(IntPtr handle);

        /// <summary>Determine if the end of the zip file entry has been reached.</summary>
        /// <param name="handle">The zip file handle opened by <see cref="unzOpenCurrentFile"/>.</param>
        /// <returns>
        ///   <para>One if the end of file was reached.</para>
        ///   <para>Zero if elsewhere.</para>
        /// </returns>
        [DllImport("zlib.dll")]
        public static extern int unzeof(IntPtr handle);

        /// <summary>Converts a CLR string to a 8 bit ANSI array of characters.</summary>
        /// <param name="str">The string to convert.</param>
        /// <returns>A 8 bit ANSI array of characters.</returns>
        public static sbyte[] StringToAnsi(string str) {
            int length = str.Length;
            sbyte[] chars = new sbyte[length + 1];
            for (int i = 0; i < length; i++) {
                chars[i] = (sbyte) str[i];
            }

            return chars;
        }

        /// <summary>Converst an 8 bit ANSI C style string to a CLR string.</summary>
        /// <param name="chars">The array of a characters that holds the string.</param>
        /// <returns>The CLR string representing the characters passed in.</returns>
        public static string AnsiToString(sbyte[] chars) {
            int length = chars.Length;
            StringBuilder builder = new StringBuilder();
            for (int i = 0; i < length; i++) {
                builder.Append((char) chars[i]);
            }
            return builder.ToString();
        }
    }

    /// <summary>List of possible error codes.</summary>
    internal enum ErrorCode : int {
        /// <summary>No error.</summary>
        Ok = 0,

        /// <summary>Unknown error.</summary>
        Error = -1,

        /// <summary>Last entry in directory reached.</summary>
        EndOfListOfFile = -100,

        /// <summary>Parameter error.</summary>
        ParameterError = -102,

        /// <summary>Zip file is invalid.</summary>
        BadZipFile = -103,

        /// <summary>Internal program error.</summary>
        InternalError = -104,

        /// <summary>Crc values do not match.</summary>
        CrcError = -105
    }

原文转自：http://www.ltesting.net