Question

I have problems in using SharpZipLib with isolated storage in WP7 to zip subfolders in isolated storage. My folder structure is like I’m having a rootFolder in isolated storage and inside that there is subFolder having some text files and more subfolders (contains .jpg and .png). I could go for Dotnetzip but I’m not sure it is available for WP7 or not and about its usage.

1. I am able to get all the file pathes in a list by recursively traversing on root folder. At present I am able to zip multiple files but only when they are inside a single folder.

2. Can’t find way to zip subFolder with correct hierarchy of folder and file structure and save it inside isolated storage. Also needs to unzip it with correct folder and file structure.

Answer 1

You can do this with SharpZipLib for Silverlight/Windows Phone 7.

The following code is based on this example and demonstrates how to zip a root folder including subfolders and files.

Short overview:

• button1_Click prepares some dummy folders and files for proof of concept: a folder root containing a file and two subfolders each also containing a file, then it calls CreateZip to compress the whole directory tree starting with root
• CreateZip prepares the zip file and starts recursive folder compression by calling CompressFolder
• CompressFolder adds all files in a given dir to the zip file and recurses into subdirectories

The code:

    using System.IO.IsolatedStorage;
    using ICSharpCode.SharpZipLib.Zip;
    using ICSharpCode.SharpZipLib.Core;
    using System.Text;

    // Recurses down the folder structure
    //
    private void CompressFolder(string path, ZipOutputStream zipStream, int folderOffset, IsolatedStorageFile isf)
    {

        string[] files = isf.GetFileNames(System.IO.Path.Combine(path, "*.*"));

        foreach (string filename in files)
        {
            string filenameWithPath = System.IO.Path.Combine(path, filename);
            string entryName = filenameWithPath.Substring(folderOffset); // Makes the name in zip based on the folder
            entryName = ZipEntry.CleanName(entryName); // Removes drive from name and fixes slash direction
            ZipEntry newEntry = new ZipEntry(entryName);
            newEntry.DateTime = isf.GetLastWriteTime(filenameWithPath).DateTime; // Note the zip format stores 2 second granularity

            // To permit the zip to be unpacked by built-in extractor in WinXP and Server2003, WinZip 8, Java, and other older code,
            // you need to do one of the following: Specify UseZip64.Off, or set the Size.
            // If the file may be bigger than 4GB, or you do not need WinXP built-in compatibility, you do not need either,
            // but the zip will be in Zip64 format which not all utilities can understand.
            //   zipStream.UseZip64 = UseZip64.Off;
            using (IsolatedStorageFileStream stream = new IsolatedStorageFileStream(filenameWithPath, System.IO.FileMode.Open, isf))
            {
                newEntry.Size = stream.Length;
            }

            zipStream.PutNextEntry(newEntry);

            // Zip the file in buffered chunks
            // the "using" will close the stream even if an exception occurs
            byte[] buffer = new byte[4096];
            using (IsolatedStorageFileStream streamReader = isf.OpenFile(filenameWithPath, System.IO.FileMode.Open))
            {
                StreamUtils.Copy(streamReader, zipStream, buffer);
            }
            zipStream.CloseEntry();
        }
        string[] folders = isf.GetDirectoryNames(System.IO.Path.Combine(path, "*.*"));
        foreach (string folder in folders)
        {
            CompressFolder(System.IO.Path.Combine(path, folder), zipStream, folderOffset, isf);
        }
    }

    // Compresses the files in the nominated folder, and creates a zip file on disk named as outPathname.
    //
    public void CreateZip(string outPathname, string password, string folderName)
    {

        using (IsolatedStorageFile isf = IsolatedStorageFile.GetUserStoreForApplication())
        {
            using (IsolatedStorageFileStream fsOut = new IsolatedStorageFileStream(outPathname, System.IO.FileMode.Create, isf))
            {
                ZipOutputStream zipStream = new ZipOutputStream(fsOut);

                zipStream.SetLevel(3); //0-9, 9 being the highest level of compression

                zipStream.Password = password;  // optional. Null is the same as not setting.

                // This setting will strip the leading part of the folder path in the entries, to
                // make the entries relative to the starting folder.
                // To include the full path for each entry up to the drive root, assign folderOffset = 0.

                // int folderOffset = folderName.Length + (folderName.EndsWith("\\") ? 0 : 1); // hu: currently not used for WP7 sample
                int folderOffset = 0;

                CompressFolder(folderName, zipStream, folderOffset, isf);

                zipStream.Close();
            }
        }
    }

    private void button1_Click(object sender, RoutedEventArgs e)
    {
        using (IsolatedStorageFile isf = IsolatedStorageFile.GetUserStoreForApplication())
        {
            isf.CreateDirectory(@"root");
            isf.CreateDirectory(@"root\subfolder1");
            isf.CreateDirectory(@"root\subfolder2");

            using (IsolatedStorageFileStream stream = new IsolatedStorageFileStream(@"root\file0.txt", System.IO.FileMode.Create, isf))
            {
                byte[] bytes = Encoding.Unicode.GetBytes("hello");
                stream.Write(bytes, 0, bytes.Length);
            }

            using (IsolatedStorageFileStream stream = new IsolatedStorageFileStream(@"root\subfolder1\file1.txt", System.IO.FileMode.Create, isf))
            {
                byte[] bytes = Encoding.Unicode.GetBytes("zip");
                stream.Write(bytes, 0, bytes.Length);
            }

            using (IsolatedStorageFileStream stream = new IsolatedStorageFileStream(@"root\subfolder2\file2.txt", System.IO.FileMode.Create, isf))
            {
                byte[] bytes = Encoding.Unicode.GetBytes("world");
                stream.Write(bytes, 0, bytes.Length);
            }

        }
        CreateZip("root.zip", null, "root");
    }