Question

I am a programmer using VS2012. I am wanting to unzip a zip file (made with Winzip, filzip or other zip compression routines) and then also be able to zip the files back up into a zip file.

What is the best library to use for this and can I please have some sample code on how to use the library?

EDIT

I am using VB.net, here is my code:

Public Function extractZipArchive() As Boolean
    Dim zipPath As String = "c:\example\start.zip"
    Dim extractPath As String = "c:\example\extract"

    Using archive As ZipArchive = ZipFile.OpenRead(zipPath)
        For Each entry As ZipArchiveEntry In archive.Entries
            If entry.FullName.EndsWith(".txt", StringComparison.OrdinalIgnoreCase) Then
                entry.ExtractToFile(Path.Combine(extractPath, entry.FullName))
            End If
        Next
    End Using
End Function

What import statements do I need to use?
Currently I have added the following:

Imports System.IO
Imports System.IO.Compression

I am getting the error:

Type ‘ZipArchive’ is not defined

How can I fix this error?

Answer 1

If you’re using Visual Studio 2012 and the .NET Framework 4.5 you can use the new compression library:

    //This stores the path where the file should be unzipped to,
    //including any subfolders that the file was originally in.
    string fileUnzipFullPath;
     
    //This is the full name of the destination file including
    //the path
    string fileUnzipFullName;
     
    //Opens the zip file up to be read
    using (ZipArchive archive = ZipFile.OpenRead(zipName))
    {
        //Loops through each file in the zip file
        foreach (ZipArchiveEntry file in archive.Entries)
        {
            //Outputs relevant file information to the console
            Console.WriteLine("File Name: {0}", file.Name);
            Console.WriteLine("File Size: {0} bytes", file.Length);
            Console.WriteLine("Compression Ratio: {0}", ((double)file.CompressedLength / file.Length).ToString("0.0%"));
     
            //Identifies the destination file name and path
            fileUnzipFullName = Path.Combine(dirToUnzipTo, file.FullName);
     
            //Extracts the files to the output folder in a safer manner
            if (!System.IO.File.Exists(fileUnzipFullName))
            {
                //Calculates what the new full path for the unzipped file should be
                fileUnzipFullPath = Path.GetDirectoryName(fileUnzipFullName);
                            
                //Creates the directory (if it doesn't exist) for the new path
                Directory.CreateDirectory(fileUnzipFullPath);
     
                //Extracts the file to (potentially new) path
                file.ExtractToFile(fileUnzipFullName);
            }
        }
    }