在.net 1.1中我们要实现压缩这一功能，一般都是用open source的SharpZipLib 或者调用J#类库。
现在在.net 2.0中增加了压缩功能，名字空间为 using System.IO.Compression;
以下是使用示例：
压缩字符串
public static string ZipString(string unCompressedString)
{
byte[] bytData = System.Text.Encoding.UTF8.GetBytes(unCompressedString);
MemoryStream ms = new MemoryStream();
Stream s = new GZipStream(ms, CompressionMode.Compress);
s.Write(bytData, 0, bytData.Length);
s.Close();
byte[] compressedData = (byte[])ms.ToArray();
return System.Convert.ToBase64String(compressedData, 0, compressedData.Length);
}
解压缩字符串
public static string UnzipString(string unCompressedString)
{
System.Text.StringBuilder uncompressedString = new System.Text.StringBuilder();
byte[] writeData = new byte[4096];
byte[] bytData = System.Convert.FromBase64String(unCompressedString);
int totalLength = 0;
int size = 0;
Stream s = new GZipStream(new MemoryStream(bytData), CompressionMode.Decompress);
while (true)
{
size = s.Read(writeData, 0, writeData.Length);
if (size > 0)
{
totalLength += size;
uncompressedString.Append(System.Text.Encoding.UTF8.GetString(writeData, 0, size));
}
else
{
break;
}
}
s.Close();
return uncompressedString.ToString();
}
压缩文件
public static bool AddZip(string srcFilename, string zipFileName)
{
if (!File.Exists(srcFilename))
return false;
bool result;
FileStream fs = null, output = null;
GZipStream zipStream = null;
try
{
fs = new FileStream(srcFilename, FileMode.Open, FileAccess.Read);
byte[] buffer = new byte[fs.Length];
fs.Read(buffer, 0, buffer.Length);
fs.Close();
if (!File.Exists(zipFileName))
{
output = File.Create(zipFileName);
zipStream = new GZipStream(output, CompressionMode.Compress);
zipStream.Write(buffer, 0, buffer.Length);
result = true;
}
else
{
result = false;
}
}
catch(Exception)
{
result = false;
}
finally
{
if (zipStream != null)
{
zipStream.Flush();
zipStream.Close();
}
}
return result;
}