//生成的压缩文件为test.zip
using (FileStream fsOut = File.Create("test.zip"))
{
 //ZipOutputStream类的构造函数需要一个流，文件流、内存流都可以，压缩后的内容会写入到这个流中。
 using (ZipOutputStream zipStream = new ZipOutputStream(fsOut))
 {
  //准备把G盘根目录下的vcredist_x86.exe文件添加到压缩包中。
  string fileName = @"G:\vcredist_x86.exe";
  FileInfo fi = new FileInfo(fileName);
  //entryName就是压缩包中文件的名称。
  string entryName = "vcredist_x86.exe";
  //ZipEntry类代表了一个压缩包中的一个项，可以是一个文件，也可以是一个目录。
  ZipEntry newEntry = new ZipEntry(entryName);
  newEntry.DateTime = fi.LastWriteTime;
  newEntry.Size = fi.Length;
  //把压缩项的信息添加到ZipOutputStream中。
  zipStream.PutNextEntry(newEntry);
  byte[] buffer = new byte[4096];
  //把需要压缩文件以文件流的方式复制到ZipOutputStream中。

  using (FileStream streamReader = File.OpenRead(fileName))
  {
   StreamUtils.Copy(streamReader, zipStream, buffer);
  }
  zipStream.CloseEntry();
  //添加多个文件
  //如果要压缩一个文件夹，就是通过遍历添加文件夹下所有的文件
  string fileName2 = @"G:\share\web.dll";
  FileInfo fi2 = new FileInfo(fileName2);

  //文件在压缩包中的路径
  string entryName2 = "share\\web.dll";
  ZipEntry newEntry2 = new ZipEntry(entryName2);
  newEntry2.DateTime = fi2.LastWriteTime;
  newEntry2.Size = fi2.Length;
  zipStream.PutNextEntry(newEntry2);
  byte[] buffer2 = new byte[4096];
  using (FileStream streamReader = File.OpenRead(fileName2))
  {
   StreamUtils.Copy(streamReader, zipStream, buffer2);
  }
  zipStream.CloseEntry();
  //使用流操作时一定要设置IsStreamOwner为false。否则很容易发生在文件流关闭后的异常。
  zipStream.IsStreamOwner = false;
  zipStream.Finish();
  zipStream.Close();
 }
}

//我们有一个字符串，希望直接写入到压缩包中的City.csv文件中。
byte[] string1 = Encoding.UTF8.GetBytes("Washington,ShangHai,TianJin,DongJing");
using (FileStream fsOut = File.Create("test1.zip"))
{
 using (ZipOutputStream zipStream = new ZipOutputStream(fsOut))
 {
  ZipEntry entry = new ZipEntry("City.csv");
  entry.DateTime = DateTime.Now;
  zipStream.PutNextEntry(entry);
  //Write方法和前面用的StreamUtils.Copy方法差不多，不过这里操作的是byte数组。
  zipStream.Write(string1, 0, string1.Length);
  zipStream.CloseEntry();
  zipStream.IsStreamOwner = false;
  zipStream.Finish();
  zipStream.Close();
 }
}

byte[] string1 = Encoding.UTF8.GetBytes("Washington,ShangHai,TianJin,DongJing");
byte[] result = null;
using (MemoryStream ms = new MemoryStream())
{
 using (ZipOutputStream zipStream = new ZipOutputStream(ms))
 {
  ZipEntry entry = new ZipEntry("City.csv");
  entry.DateTime = DateTime.Now;
  zipStream.PutNextEntry(entry);
  zipStream.Write(string1, 0, string1.Length);
  zipStream.CloseEntry();
  zipStream.IsStreamOwner = false;
  zipStream.Finish();
  zipStream.Close();
  ms.Position = 0;

  //压缩后的数据被保存到了byte[]数组中。
  result = ms.ToArray();
 }
}

byte[] string1 = Encoding.UTF8.GetBytes("Washington,ShangHai,TianJin,DongJing");
using (FileStream fsOut = File.Create("test1.zip"))
{
 using (ZipOutputStream zipStream = new ZipOutputStream(fsOut))
 {
  //文件名变成了中文
  ZipEntry entry = new ZipEntry("城市.csv");
  entry.DateTime = DateTime.Now;
  ...
 }
}

entry.IsUnicodeText = true;