需要引用如下命名空间：

using System.IO;  using System.IO.Compression;

实现如下：

string sourceFile=@"C:\1.txt";  string destinationFile=@"D:\2.zip";  private const long BUFFER_SIZE = 20480;    if ( File.Exists ( sourceFile ))  {      FileStream sourceStream = null;      FileStream destinationStream = null;      GZipStream compressedStream = null;      try      {          // Read the bytes from the source file into a byte array          sourceStream = new FileStream ( sourceFile, FileMode.Open, FileAccess.Read, FileShare.Read );            // Open the FileStream to write to          destinationStream = new FileStream ( destinationFile, FileMode.OpenOrCreate, FileAccess.Write );            // Create a compression stream pointing to the destiantion stream          compressedStream = new DeflateStream ( destinationStream, CompressionMode.Compress, true );      long bufferSize = sourceStream.Length < BUFFER_SIZE ? sourceStream.Length : BUFFER_SIZE;         byte[] buffer = new byte[bufferSize];         int bytesRead = 0;         long bytesWritten = 0;         while ((bytesRead = sourceStream.Read(buffer, 0, buffer.Length)) != 0)         {             compressedStream.Write(buffer, 0, bytesRead);             bytesWritten += bufferSize;         }           }      catch ( ApplicationException ex )      {          Console.WriteLine(ex.Message);      }      finally      {          // Make sure we allways close all streams          if ( sourceStream != null )              sourceStream.Close ( );            if ( compressedStream != null )              compressedStream.Close ( );            if ( destinationStream != null )              destinationStream.Close ( );      }  }