using System;
using System.IO;
using System.IO.Compression;
public class Zip
{
/// <summary>
/// 压缩
/// </summary>
/// <param name="sourceFile">源文件名,如a.txt</param>
/// <param name="destinationFile">目标文件名,如a.rar</param>
public static void CompressFile(string sourceFile, string destinationFile)
{
if (!File.Exists(sourceFile)) throw new FileNotFoundException();
using (FileStream sourceStream = new FileStream(sourceFile, FileMode.Open, FileAccess.Read, FileShare.Read))
{
byte [] buffer = new byte[sourceStream.Length];
int checkCounter = sourceStream.Read(buffer, 0, buffer.Length);
if (checkCounter != buffer.Length) throw new ApplicationException();
using (FileStream destinationStream = new FileStream(destinationFile, FileMode.OpenOrCreate, FileAccess.Write))
{
using (GZipStream compressedStream = new GZipStream(destinationStream, CompressionMode.Compress, true))
{
compressedStream.Write(buffer, 0, buffer.Length);
}
}
}
}
/// <summary>
/// 解压缩
/// </summary>
/// <param name="sourceFile">源文件名,如a.rar</param>
/// <param name="destinationFile">目标文件名,如a.txt</param>
public static void DecompressFile(string sourceFile, string destinationFile)
{
if (!File.Exists( sourceFile)) throw new FileNotFoundException();
using (FileStream sourceStream = new FileStream(sourceFile, FileMode.Open))
{
byte [] quartetBuffer = new byte[4];
int position = (int)sourceStream.Length - 4;
sourceStream.Position = position;
sourceStream.Read(quartetBuffer, 0, 4);
sourceStream.Position = 0;
int checkLength = BitConverter.ToInt32(quartetBuffer, 0);
byte[] buffer = new byte[checkLength + 100];
using (GZipStream decompressedStream = new GZipStream(sourceStream, CompressionMode.Decompress, true))
{
int total = 0;
for (int offset = 0; ; )
{
int bytesRead = decompressedStream.Read(buffer, offset, 100);
if (bytesRead == 0) break;
offset += bytesRead;
total += bytesRead;
}
using (FileStream destinationStream = new FileStream(destinationFile, FileMode.Create))
{
destinationStream.Write(buffer, 0, total);
destinationStream.Flush();
}
}
}
}
}
