using System.IO.Compression;

string TOZipPath = String.Format("~/Static/ZIP/{0}", DirName);                  //需要压缩的源文件
string TOZipFilePath = String.Format("~/Static/ZIP/{0}", DirName + ".zip");  //压缩成新的Zip文件

try
{
　　ZipFile.CreateFromDirectory(Server.MapPath(TOZipPath), Server.MapPath(TOZipFilePath));
}
catch (Exception ex){}