File compression and decompression in asp. NET (3 ways)

In. NET, zip can be compressed and decompressed in many ways: 1. System. IO. Packaging; 2. Use the third class library; 3. It is implemented by adding ZipArchive, ZipFile and other classes in System. IO. Compression namespace.

1. Compression and decompression using System. IO. Packaging

Package is an abstract class that can be used to organize objects into a single entity in a defined physical format for portability and efficient access. The ZIP file is the main physical format of Package. Other Package implementations can use other physical formats (such as XML documents, databases, or Web services. Similar to file systems, items contained in Package are referenced in hierarchically organized folders and files. Although Package is an abstract class, Package. Open methods use ZipPackage derived classes by default.

System. IO. Packaging Under the WindowsBase. dll assembly, you need to add a reference to WindowsBase when you use it.

1. Compress the whole folder into 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. Add a single file to the zip file

 /// <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 file decompression

/// <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);
   }
  }

Using the Package zip file automatically generates [Content_Type] in the zip file. xml, which describes the supported file formats for zip file extraction.

  <?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>

Similarly, if the zip file does not contain the [Content_Type]. xml file, or the [Content_Type]. xml file does not contain a description of the corresponding extension (manually added [Content_Type]. xml is also OK), the file cannot be unzipped.

2. Use the third-party class library

The compression and decompression of zip are compared with SharpZipLib and DotNetZip.

1. SharpZipLib, also known as "# ziplib", is based on GPL open source and supports compression and decompression of Zip, GZip, Tar and BZip2.

Supports. NET 1.1, NET 2.0 (3.5, 4.0).

(1) zip compression

 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) Decompress 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 is based on "WS-PL" open source, which is relatively simple to use

(1) Compression

  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) Decompression

 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);
   }
  }
 }

3. Compression and decompression using ZipArchive, ZipFile, etc. in. NET 4.5

 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);
   } 
  }