Zip / Unzip folders and files with C#

The .NET Framework includes GZipStream and related classes, but they only support compression, not the standard ZIP file structure. This article explains how you can handle correctly zipping and unzipping folders and files including using a zip password.

A-well-a don't you know about the bird?
Well, everybody knows that the bird is the word!  --The Trashmen (1963)

The .NET Framework has GzipStream and DeflateStream classes for compression tasks, but they do not support the standard ZIP file / folder FileEntry mechanism to zip a folder with all its files and subfolders.

Fortunately, the ICSharpCode SharpZipLib project does support this, as well as passwords for zip files and compression level.

Here is a utility class I wrote that handles zipping or unzipping a folder with all its subfolders and contained files, using SharpZipLib:

using System;
using System.Collections;
using System.IO;
using ICSharpCode.SharpZipLib.Zip;

namespace FolderZipper
{
    public static class ZipUtil
    {
        public static void ZipFiles(string inputFolderPath, string outputPathAndFile, string password)
        {
            ArrayList ar = GenerateFileList(inputFolderPath); // generate file list
            int TrimLength = (Directory.GetParent(inputFolderPath)).ToString().Length;
            // find number of chars to remove     // from orginal file path
            TrimLength += 1; //remove '\'
            FileStream ostream;
            byte[] obuffer;
            string outPath = inputFolderPath + @"\" + outputPathAndFile;
            ZipOutputStream oZipStream = new ZipOutputStream(File.Create(outPath)); // create zip stream
            if (password != null && password != String.Empty)
                oZipStream.Password = password;
            oZipStream.SetLevel(9); // maximum compression
            ZipEntry oZipEntry;
            foreach (string Fil in ar) // for each file, generate a zipentry
            {
                oZipEntry = new ZipEntry(Fil.Remove(0, TrimLength));
                oZipStream.PutNextEntry(oZipEntry);

                if (!Fil.EndsWith(@"/")) // if a file ends with '/' its a directory
                {
                    ostream = File.OpenRead(Fil);
                    obuffer = new byte[ostream.Length];
                    ostream.Read(obuffer, 0, obuffer.Length);
                    oZipStream.Write(obuffer, 0, obuffer.Length);
                }
            }
            oZipStream.Finish();
            oZipStream.Close();
        }


        private static ArrayList GenerateFileList(string Dir)
        {
            ArrayList fils = new ArrayList();
            bool Empty = true;
            foreach (string file in Directory.GetFiles(Dir)) // add each file in directory
            {
                fils.Add(file);
                Empty = false;
            }

            if (Empty)
            {
                if (Directory.GetDirectories(Dir).Length == 0)
                    // if directory is completely empty, add it
                {
                    fils.Add(Dir + @"/");
                }
            }

            foreach (string dirs in Directory.GetDirectories(Dir)) // recursive
            {
                foreach (object obj in GenerateFileList(dirs))
                {
                    fils.Add(obj);
                }
            }
            return fils; // return file list
        }


        public static void UnZipFiles(string zipPathAndFile, string outputFolder, string password, bool deleteZipFile)
        {
            ZipInputStream s = new ZipInputStream(File.OpenRead(zipPathAndFile));
            if (password != null && password != String.Empty)
                s.Password = password;
            ZipEntry theEntry;
            string tmpEntry = String.Empty;
            while ((theEntry = s.GetNextEntry()) != null)
            {
                string directoryName = outputFolder;
                string fileName = Path.GetFileName(theEntry.Name);
                // create directory 
                if (directoryName != "")
                {
                    Directory.CreateDirectory(directoryName);
                }
                if (fileName != String.Empty)
                {
                    if (theEntry.Name.IndexOf(".ini") < 0)
                    {
                        string fullPath = directoryName + "\\" + theEntry.Name;
                        fullPath = fullPath.Replace("\\ ", "\\");
                        string fullDirPath = Path.GetDirectoryName(fullPath);
                        if (!Directory.Exists(fullDirPath)) Directory.CreateDirectory(fullDirPath);
                        FileStream streamWriter = File.Create(fullPath);
                        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;
                            }
                        }
                        streamWriter.Close();
                    }
                }
            }
            s.Close();
            if (deleteZipFile)
                File.Delete(zipPathAndFile);
        }
    }
}

Hi Pete,
Subject: Regarding "How to zip one excel file with the given utility class".

Thankyou very much since you have given one very beautiful article. But I could not understand how to use this utility class to zip and store one excel file.
My concern is:
01. How to zip one excel file with the given utility class?
02. How to store the .zipped file at one location?

Kind Regards,
Ashok kumar.
Software Engineer from Bangalore/India.

Peter,

If I understand you correctly the standard framework libraries do not allow creating of ZIP files themselves but only compression in the life of the app.  Correct?  So SharpZipLib is the best alternative in your opinion?  I need to take photos and files in an ASP.NET app from a database and combine in a zip file for download to the user.  Thanks in advance.

Doug - Missoula, MT

See this posting at Codeplex to help with this as of late

http://weblogs.asp.net/jgalloway/archive/2007/10/25/creating-zip-archives-in-net-without-an-external-library-like-sharpziplib.aspx

      Now we are done with generating a cryatal report  with CR server XI and exported this to byte[] and decoded to pdf formated base64string. And this base64string will be saved in sql database.

      And using asp.net.mail we will send the mail with encoded base64string as attachememt. So the receiver of the mail will be able to open the attachent as PDF.[following this concept to schedule the report]

      Here we need your help. Because of constraint of mailing attachemnt size we are searching for possible solution. Is it possible to split the Exported byte[] in to muliple .rar files. And rar files should not be created physically but as stream. This stream will be converted to base64string and saved in database for the use of send mail and Receiver will extract this multiple rar files in one .pdf report?

 or could you able suggest different way?

Hello Peter

I am using your methods to zip all files in a perticular folder.  The function is doing the required operation, but after zipping the files when I am trying to delete the files its showing me the following error.

"The process cannot access the file because it is being used by another process."

I have closed all the file stream after zipping the file,

Can you suggest me why I am getting this error.

Thanks

Debarati

Hello Peter

Thanks for your response. I am using the same code as provided by you. I am furnishing the code below.

public static void ZipFiles(string inputFolderPath, string outputPathAndFile, string password)

FileStream ostream = null;

ZipOutputStream oZipStream = null;

ZipEntry oZipEntry = null;

byte[] obuffer;

//If the Zip stream already exists then

//My Input folder is c:\Test which contains 7 .txt files.

string outPath = inputFolderPath + @"\" + outputPathAndFile;

try

if (File.Exists(outPath))

File.Delete(outPath);

ArrayList ar = GenerateFileList(inputFolderPath); // generate file list

//remove the log file from the list.

int TrimLength = (Directory.GetParent(inputFolderPath)).ToString().Length;

// find number of chars to remove // from orginal file path

TrimLength += 1; 

oZipStream = new ZipOutputStream(File.Create(outPath)); // create zip stream

if (password != null && password != String.Empty)

oZipStream.SetLevel(9); // maximum compression

foreach (string Fil in ar) // for each file, generate a zipentry

oZipEntry = new ZipEntry(Fil.Remove(0, TrimLength));

if (!Fil.EndsWith(@"/")) // if a file ends with '/' its a directory

ostream = File.OpenRead(Fil);

obuffer = new byte[ostream.Length];

catch (Exception ex)

string strmg = ex.Message.ToString();

finally

ostream = null;

oZipStream = null;

oZipEntry = null;

obuffer = null;

//Delete the directory and all the files inside it.

Directory.Delete(inputFolderPath,true);

Compilation Error

BC30002: Type 'ZipInputStream' is not defined

Namespace or type specified in the Imports 'ICSharpCode.SharpZipLib.Zip' doesn't contain any public member or cannot be found

can u please help me

it worked fine on my local system, but it gives error online
i uploaded the dll in the bin folder online

thank u

        oZipStream.Write(obuffer, 0, obuffer.Length);

        ostream.Close(); // stop read handle leak

Thanks for the Code

Cheers

Colin

hi,

   i'm using the exact code given above.

 i'm also using

path = "c:\\test\\";

IcsZipper.ZipUtil.ZipFiles(path, "c:\\", "");

but i get the debug error: The given path's format is not supported.

at line

Please advice:)

I am trying to zip and unzip PPTX(2007) with the help of ICSharpCode.SharpZipLib.Zip in Memory stream.

I am trying to updated those xml files (Unzipped PPTX files) with input data,without disturbing the structure of the xml .

Finally I am ziping those xml files and writing to PPTX .

When I tried to open this pptx,throws an error saying Files are corrupted.

 my Question is

Is there any chance of corrupting the xml files while unzip in memory stream.

Plese find the sample code ;