C#压缩单个zip格式文件

C#压缩单个zip格式文件

using System.IO;
using System.IO.Compression;
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 ( );
            }
        }