c# 文件压缩zip或将zip文件解压

1.必须Dll：
ICSharpCode.SharpZipLib.dll。可从Nutget程序包中获取。
2.压缩文件

/// 

/// 压缩文件成zip
/// 
/// 压缩成zip文件的绝对路径
/// 被压缩指定文件的名字
/// 
/// 
public bool CreateZipFile(string fileZip,string fileName, string zipFilePath)
       {
           bool isZip = false;
            if (!Directory.Exists(zipFilePath))
            {
               Logger.Info($"Cannot find directory {zipFilePath}", false, "FileToZip");
               return isZip;
            }
            try
            {
                string[] filenames = Directory.GetFiles(zipFilePath);
                using (ZipOutputStream s = new ZipOutputStream(File.Create(fileZip)))
                {
                    s.SetLevel(9); // 压缩级别 0-9
                    //s.Password = "123"; //Zip压缩文件密码
                    byte[] buffer = new byte[4096]; //缓冲区大小
                    foreach (string file in filenames.ToList())
                    {
                        if (file== zipFilePath+fileName)//指定被压缩文件的绝对路径
                        {
                            ZipEntry entry = new ZipEntry(Path.GetFileName(file));
                            entry.DateTime = DateTime.Now;
                            s.PutNextEntry(entry);
                            using (FileStream fs = File.OpenRead(file))
                            {
                                int sourceBytes;
                                do
                                {
                                    sourceBytes = fs.Read(buffer, 0, buffer.Length);
                                    s.Write(buffer, 0, sourceBytes);
                                } while (sourceBytes > 0);
                                fs.Close();
                                fs.Dispose();
                            }
                            break;
                        }

                    }
                    s.Finish();
                    s.Close();
                    isZip = true;
                }
            }
            catch (Exception ex)
            {
                Logger.Info($"Exception during processing {0}", false, "FileToZip");
            }
           return isZip;
       }

2.将zip文件解压

/// 

/// 解压文件
/// 
/// 压缩文件的绝对路径
 public  void UnZipFile(string zipFilePath)
        {
            if (!File.Exists(zipFilePath))
            {
                Logger.Info($"Cannot find file {zipFilePath}", false, "FileToZip");
                return;
            }

            using (ZipInputStream s = new ZipInputStream(File.OpenRead(zipFilePath)))
            {

                ZipEntry theEntry;
                while ((theEntry = s.GetNextEntry()) != null)
                {

                    string directoryName = Path.GetDirectoryName(theEntry.Name);
                    string fileName = Path.GetFileName(theEntry.Name);

                    // create directory
                    if (directoryName?.Length > 0)
                    {
                        Directory.CreateDirectory(directoryName);
                    }

                    if (!string.IsNullOrEmpty(fileName))
                    {
                        using (FileStream streamWriter = File.Create(theEntry.Name))
                        {

                            int size = 2048;
                            byte[] data = new byte[2048];
                            while (true)
                            {
                                size = s.Read(data, 0, data.Length);
                                if (size > 0)
                                {
                                    streamWriter.Write(data, 0, size);
                                }
                                else
                                {
                                    break;
                                }
                            }
                        }
                    }
                }
            }
        }

4.其它：其中的Logger是Log4的用法。