.NET中zip的压缩和解压

      在.NET可以通过多种方式实现zip的压缩和解压：1、使用System.IO.Packaging；2、使用第三方类库；3、通过 System.IO.Compression 命名空间中新增的ZipArchive、ZipFile等类实现。

     一、使用System.IO.Packaging压缩和解压

     Package为一个抽象类，可用于将对象组织到定义的物理格式的单个实体中，从而实现可移植性与高效访问。ZIP 文件是Package的主物理格式。 其他Package实现可以使用其他物理格式（如 XML 文档、数据库或 Web 服务。与文件系统类似，在分层组织的文件夹和文件中引用 Package 中包含的项。虽然 Package 是抽象类，但 Package.Open 方法默认使用 ZipPackage 派生类。

    System.IO.Packaging在WindowsBase.dll程序集下，使用时需要添加对WindowsBase的引用。

    1、将整个文件夹压缩成zip

/// <summary>
        /// Add a folder along with its subfolders to a Package
        /// </summary>
        /// <param name="folderName">The folder to add</param>
        /// <param name="compressedFileName">The package to create</param>
        /// <param name="overrideExisting">Override exsisitng files</param>
        /// <returns></returns>
        static bool PackageFolder(string folderName, string compressedFileName, bool overrideExisting)
        {
            if (folderName.EndsWith(@"\"))
                folderName = folderName.Remove(folderName.Length - 1);
            bool result = false;
            if (!Directory.Exists(folderName))
            {
                return result;
            }

            if (!overrideExisting && File.Exists(compressedFileName))
            {
                return result;
            }
            try
            {
                using (Package package = Package.Open(compressedFileName, FileMode.Create))
                {
                    var fileList = Directory.EnumerateFiles(folderName, "*", SearchOption.AllDirectories);
                    foreach (string fileName in fileList)
                    {
                       
                        //The path in the package is all of the subfolders after folderName
                        string pathInPackage;
                        pathInPackage = Path.GetDirectoryName(fileName).Replace(folderName, string.Empty) + "/" + Path.GetFileName(fileName);

                        Uri partUriDocument = PackUriHelper.CreatePartUri(new Uri(pathInPackage, UriKind.Relative));
                        PackagePart packagePartDocument = package.CreatePart(partUriDocument,"", CompressionOption.Maximum);
                        using (FileStream fileStream = new FileStream(fileName, FileMode.Open, FileAccess.Read))
                        {
                            fileStream.CopyTo(packagePartDocument.GetStream());
                        }
                    }
                }
                result = true;
            }
            catch (Exception e)
            {
                throw new Exception("Error zipping folder " + folderName, e);
            }
           
            return result;
        }

      2、将单个文件添加到zip文件中

       /// <summary>
        /// Compress a file into a ZIP archive as the container store
        /// </summary>
        /// <param name="fileName">The file to compress</param>
        /// <param name="compressedFileName">The archive file</param>
        /// <param name="overrideExisting">override existing file</param>
        /// <returns></returns>
        static bool PackageFile(string fileName, string compressedFileName, bool overrideExisting)
        {
            bool result = false;

            if (!File.Exists(fileName))
            {
                return result;
            }

            if (!overrideExisting && File.Exists(compressedFileName))
            {
                return result;
            }

            try
            {
                Uri partUriDocument = PackUriHelper.CreatePartUri(new Uri(Path.GetFileName(fileName), UriKind.Relative));
               
                using (Package package = Package.Open(compressedFileName, FileMode.OpenOrCreate))
                {
                    if (package.PartExists(partUriDocument))
                    {
                        package.DeletePart(partUriDocument);
                    } 

                    PackagePart packagePartDocument = package.CreatePart(partUriDocument, "", CompressionOption.Maximum);
                    using (FileStream fileStream = new FileStream(fileName, FileMode.Open, FileAccess.Read))
                    {
                        fileStream.CopyTo(packagePartDocument.GetStream());
                    }
                }
                result = true;
            }
            catch (Exception e)
            {
                throw new Exception("Error zipping file " + fileName, e);
            }
            
            return result;
        }

       3、zip文件解压

/// <summary>
        /// Extract a container Zip. NOTE: container must be created as Open Packaging Conventions (OPC) specification
        /// </summary>
        /// <param name="folderName">The folder to extract the package to</param>
        /// <param name="compressedFileName">The package file</param>
        /// <param name="overrideExisting">override existing files</param>
        /// <returns></returns>
        static bool UncompressFile(string folderName, string compressedFileName, bool overrideExisting)
        {
            bool result = false;
            try
            {
                if (!File.Exists(compressedFileName))
                {
                    return result;
                }

                DirectoryInfo directoryInfo = new DirectoryInfo(folderName);
                if (!directoryInfo.Exists)
                    directoryInfo.Create();

                using (Package package = Package.Open(compressedFileName, FileMode.Open, FileAccess.Read))
                {
                    foreach (PackagePart packagePart in package.GetParts())
                    {
                        ExtractPart(packagePart, folderName, overrideExisting);
                    }
                }

                result = true;
            }
            catch (Exception e)
            {
                throw new Exception("Error unzipping file " + compressedFileName, e);
            }
            
            return result;
        }

        static void ExtractPart(PackagePart packagePart, string targetDirectory, bool overrideExisting)
        {
            string stringPart = targetDirectory + HttpUtility.UrlDecode(packagePart.Uri.ToString()).Replace('\\', '/');

            if (!Directory.Exists(Path.GetDirectoryName(stringPart)))
                Directory.CreateDirectory(Path.GetDirectoryName(stringPart));

            if (!overrideExisting && File.Exists(stringPart))
                return;
            using (FileStream fileStream = new FileStream(stringPart, FileMode.Create))
            {
                packagePart.GetStream().CopyTo(fileStream);
            }
        }

      使用Package压缩文件会在zip文件自动生成[Content_Type].xml，用来描述zip文件解压支持的文件格式。

<?xml version="1.0" encoding="utf-8" ?> 
<Types xmlns="http://schemas.openxmlformats.org/package/2006/content-types">
    <Default Extension="vsixmanifest" ContentType="text/xml" /> 
    <Default Extension="dll" ContentType="application/octet-stream" /> 
    <Default Extension="png" ContentType="application/octet-stream" /> 
    <Default Extension="txt" ContentType="text/plain" /> 
    <Default Extension="pkgdef" ContentType="text/plain" /> 
</Types>

 

      同样，如果zip文件不包含[Content_Type].xml文件，或者[Content_Type].xml文件不包含所对应扩展名的描述（手动添加的[Content_Type].xml也是可以），将无法解压文件。

      二、使用第三方类库

      zip的压缩和解压使用比较的有SharpZipLib和DotNetZip。

      1、SharpZipLib，也称为“#ziplib”，基于GPL开源，支持Zip，GZip，Tar和BZip2的压缩和解压缩。

      支持.NET 1.1,NET 2.0（3.5、4.0）.

      （1）zip压缩

public static void Zip(string SrcFile, string DstFile, int BufferSize)
{
    FileStream fileStreamIn = new FileStream
		(SrcFile, FileMode.Open, FileAccess.Read);
    FileStream fileStreamOut = new FileStream
		(DstFile, FileMode.Create, FileAccess.Write);
    ZipOutputStream zipOutStream = new ZipOutputStream(fileStreamOut);
    byte[] buffer = new byte<buffersize />;
    ZipEntry entry = new ZipEntry(Path.GetFileName(SrcFile));
    zipOutStream.PutNextEntry(entry);
    int size;
    do
    {
        size = fileStreamIn.Read(buffer, 0, buffer.Length);
        zipOutStream.Write(buffer, 0, size);
    } while (size > 0);
    zipOutStream.Close();
    fileStreamOut.Close();
    fileStreamIn.Close();
}

       （2）解压zip

public static void UnZip(string SrcFile, string DstFile, int BufferSize)
{
    FileStream fileStreamIn = new FileStream
		(SrcFile, FileMode.Open, FileAccess.Read);
    ZipInputStream zipInStream = new ZipInputStream(fileStreamIn);
    ZipEntry entry = zipInStream.GetNextEntry();
    FileStream fileStreamOut = new FileStream
		(DstFile + @"\" + entry.Name, FileMode.Create, FileAccess.Write);
    int size;
    byte[] buffer = new byte<buffersize />;
    do
    {
        size = zipInStream.Read(buffer, 0, buffer.Length);
        fileStreamOut.Write(buffer, 0, size);
    } while (size > 0);
    zipInStream.Close();
    fileStreamOut.Close();
    fileStreamIn.Close();
}

      2、DotNetLib，是基于”WS-PL”开源，使用比较简单
     (1)压缩

using (ZipFile zip = new ZipFile())
  {
    zip.AddFile("ReadMe.txt");
    zip.AddFile("7440-N49th.png");
    zip.AddFile("2008_Annual_Report.pdf");        
    zip.Save("Archive.zip");
  }

     （2）解压

private void MyExtract()
  {
      string zipToUnpack = "C1P3SML.zip";
      string unpackDirectory = "Extracted Files";
      using (ZipFile zip1 = ZipFile.Read(zipToUnpack))
      {
          // here, we extract every entry, but we could extract conditionally
          // based on entry name, size, date, checkbox status, etc.  
          foreach (ZipEntry e in zip1)
          {
            e.Extract(unpackDirectory, ExtractExistingFileAction.OverwriteSilently);
          }
       }
    }

    三、在.NET 4.5使用ZipArchive、ZipFile等类压缩和解压

        static void Main(string[] args)
        {
            string ZipPath = @"c:\users\exampleuser\start.zip";
            string ExtractPath = @"c:\users\exampleuser\extract";
            string NewFile = @"c:\users\exampleuser\NewFile.txt";

            using (ZipArchive Archive = ZipFile.Open(ZipPath, ZipArchiveMode.Update))
            {
                Archive.CreateEntryFromFile(NewFile, "NewEntry.txt");
                Archive.ExtractToDirectory(ExtractPath);
            } 
        }