Sub Main()
	Dim sZipFilePath As String = "..\..\test.zip"
	File.Delete(sZipFilePath)

	CreateArchive(sZipFilePath)
	Dim decryptionSettings As DecryptionSettings = EncryptionSettings.CreateDecryptionSettings()
	AddHandler decryptionSettings.PasswordRequired, AddressOf DecryptionSettings_PasswordRequired
	Dim compressionSettings As CompressionSettings = Nothing
	Dim encoding As Encoding = Nothing
	Using oFS As FileStream = File.Open(sZipFilePath, FileMode.OpenOrCreate)


		Using oArchive As ZipArchive = ZipArchive.Update(oFS, encoding, compressionSettings, decryptionSettings)
			Using entry As ZipArchiveEntry = oArchive.CreateEntry("newText.txt")
				Dim writer As StreamWriter = New StreamWriter(entry.Open())
				writer.WriteLine("Hello world!")
				writer.Flush()
			End Using
		End Using
	End Using
End Sub

Private Sub CreateArchive(sZipFilePath As String)
	Using stream As Stream = File.Open(sZipFilePath, FileMode.Create)
		Dim _encryptionSettings As PasswordEncryptionSettings = EncryptionSettings.CreatePkzipPasswordEncryptionSettings()
		_encryptionSettings.Password = "telerik"
		Dim compressionSettings As CompressionSettings = Nothing
		Dim encoding As Encoding = Nothing

		Using archive As ZipArchive = ZipArchive.Create(stream, encoding, compressionSettings, _encryptionSettings)

			Using entry As ZipArchiveEntry = archive.CreateEntry("text.txt")
				Dim writer As StreamWriter = New StreamWriter(entry.Open())
				writer.WriteLine("Hello world!")
				writer.Flush()
			End Using
		End Using
	End Using
End Sub

Private Sub DecryptionSettings_PasswordRequired(ByVal sender As Object, ByVal e As PasswordRequiredEventArgs)
	e.Password = "telerik"
End Sub

ZipArchive archive = new ZipArchive(stream, ZipArchiveMode.Create, true, encoding, compressionSettings, encryptionSettings)

ZipArchive oArchive = new ZipArchive(stream, ZipArchiveMode.Update, true, encoding, compressionSettings, decryptionSettings)

Imports System.IO
Imports System.Text
Imports Telerik.Windows.Zip

Module Module1

    Sub Main()
        Dim sZipFilePath As String = "..\..\test.zip"
        File.Delete(sZipFilePath)

        CreateArchive(sZipFilePath)

        Dim decryptionSettings As DecryptionSettings = EncryptionSettings.CreateDecryptionSettings()
        AddHandler decryptionSettings.PasswordRequired, AddressOf DecryptionSettings_PasswordRequired
        Dim compressionSettings As CompressionSettings = Nothing
        Dim encoding As Encoding = Nothing
        Using oFS As FileStream = File.Open(sZipFilePath, FileMode.OpenOrCreate)


            Using oArchive As ZipArchive = ZipArchive.Update(oFS, encoding, compressionSettings, decryptionSettings)
                For Each entry As ZipArchiveEntry In oArchive.Entries
                    Using entryStream As Stream = entry.Open()
                        Dim reader As New StreamReader(entryStream)
                        Dim content As String = reader.ReadToEnd()

                        entryStream.Seek(0, SeekOrigin.End)
                        Dim writer As New StreamWriter(entryStream)
                        writer.WriteLine("Updated line.")
                        writer.Flush()
                    End Using
                Next
            End Using
        End Using
    End Sub

    Private Sub CreateArchive(sZipFilePath As String)
        Using stream As Stream = File.Open(sZipFilePath, FileMode.Create)
            Dim encryptionSettings As PasswordEncryptionSettings = encryptionSettings.CreatePkzipPasswordEncryptionSettings()
            encryptionSettings.Password = "MyPassword"
            Dim compressionSettings As CompressionSettings = Nothing
            Dim encoding As Encoding = Nothing

            Using archive As ZipArchive = ZipArchive.Create(stream, encoding, compressionSettings, encryptionSettings)

                Using entry As ZipArchiveEntry = archive.CreateEntry("text.txt")
                    Dim writer As StreamWriter = New StreamWriter(entry.Open())
                    writer.WriteLine("Hello world!")
                    writer.Flush()
                End Using
            End Using
        End Using
    End Sub

    Private Sub DecryptionSettings_PasswordRequired(ByVal sender As Object, ByVal e As PasswordRequiredEventArgs)
        e.Password = "MyPassword"
    End Sub

End Module

    Sub Main()
        Dim sZipFilePath As String = "..\..\test.zip"
        File.Delete(sZipFilePath)

        CreateArchive(sZipFilePath)

        Dim decryptionSettings As DecryptionSettings = EncryptionSettings.CreateDecryptionSettings()
        AddHandler decryptionSettings.PasswordRequired, AddressOf DecryptionSettings_PasswordRequired
        Dim compressionSettings As CompressionSettings = Nothing
        Dim encoding As Encoding = Nothing
        Using oFS As FileStream = File.Open(sZipFilePath, FileMode.OpenOrCreate)


            Using oArchive As ZipArchive = ZipArchive.Update(oFS, encoding, compressionSettings, decryptionSettings)
                For Each entry As ZipArchiveEntry In oArchive.Entries
                    Using entryStream As Stream = entry.Open()
                        Dim reader As New StreamReader(entryStream)
                        Dim content As String = reader.ReadToEnd()

                        entryStream.Seek(0, SeekOrigin.End)
                        Dim writer As New StreamWriter(entryStream)
                        writer.WriteLine("Updated line.")
                        writer.Flush()
                    End Using
                Next
            End Using
        End Using
    End Sub

    Private Sub CreateArchive(sZipFilePath As String)
        Using stream As Stream = File.Open(sZipFilePath, FileMode.Create)
            Dim encryptionSettings As PasswordEncryptionSettings = encryptionSettings.CreatePkzipPasswordEncryptionSettings()
            encryptionSettings.Password = "MyPassword"
            Dim compressionSettings As CompressionSettings = Nothing
            Dim encoding As Encoding = Nothing

            Using archive As ZipArchive = ZipArchive.Create(stream, encoding, compressionSettings, encryptionSettings)

                Using entry As ZipArchiveEntry = archive.CreateEntry("text.txt")
                    Dim writer As StreamWriter = New StreamWriter(entry.Open())
                    writer.WriteLine("Hello world!")
                    writer.Flush()
                End Using
            End Using
        End Using
    End Sub

    Private Sub DecryptionSettings_PasswordRequired(ByVal sender As Object, ByVal e As PasswordRequiredEventArgs)
        e.Password = "MyPassword"
    End Sub

        static void Main(string[] args)
        {
            string archiveFileName = @"..\..\myzip.zip";
            string sourceDirectoryName = @"..\..\Folder";
            File.Delete(archiveFileName);
            Telerik.Windows.Zip.Extensions.ZipFile.CreateFromDirectory(sourceDirectoryName, archiveFileName, Telerik.Windows.Zip.CompressionLevel.Optimal, true);

            using (Stream stream = File.Open(archiveFileName, FileMode.Open))
            {

            }
        }

        static void Main(string[] args)
        {
            string archiveFileName = @"..\..\myzip.zip";
            string sourceDirectoryName = @"..\..\Folder";
            File.Delete(archiveFileName);

          //  Telerik.Windows.Zip.Extensions.ZipFile.CreateFromDirectory(sourceDirectoryName, archiveFileName, Telerik.Windows.Zip.CompressionLevel.Optimal, true);
            CreateFromDirectory(sourceDirectoryName, archiveFileName, Telerik.Windows.Zip.CompressionLevel.Optimal, true);

            using (Stream stream = File.Open(archiveFileName, FileMode.Open))
            {

            }
        }

        private static void CreateFromDirectory(string sourceDirectoryName, string destinationArchiveFileName, Telerik.Windows.Zip.CompressionLevel compressionLevel, bool includeBaseDirectory)
        {
            Encoding entryNameEncoding = null;
            DeflateSettings compressionSettings = new DeflateSettings()
            {
                CompressionLevel = compressionLevel,
                HeaderType = CompressedStreamHeader.None
            };
            char[] directorySeparatorChar = new char[] { Path.DirectorySeparatorChar, Path.AltDirectorySeparatorChar };

            sourceDirectoryName = Path.GetFullPath(sourceDirectoryName);
            destinationArchiveFileName = Path.GetFullPath(destinationArchiveFileName);
            FileStream fileStream = File.Open(destinationArchiveFileName, FileMode.CreateNew, FileAccess.Write, FileShare.None); ;
            using (ZipArchive zipArchive = new ZipArchive(fileStream, ZipArchiveMode.Create,false,  entryNameEncoding))
            {
                bool empty = true;

                DirectoryInfo directoryInfo = new DirectoryInfo(sourceDirectoryName);
                string fullName = directoryInfo.FullName;
                if (includeBaseDirectory && directoryInfo.Parent != null)
                {
                    fullName = directoryInfo.Parent.FullName;
                }

                foreach (FileSystemInfo fileSystemInfo in directoryInfo.EnumerateFileSystemInfos("*", SearchOption.AllDirectories))
                {
                    empty = false;

                    int length = fileSystemInfo.FullName.Length - fullName.Length;
                    string entryName = fileSystemInfo.FullName.Substring(fullName.Length, length);
                    entryName = entryName.TrimStart(directorySeparatorChar);

                    DirectoryInfo subfolder = fileSystemInfo as DirectoryInfo;
                    if (subfolder != null)
                    {
                        if (IsDirectoryEmpty(subfolder))
                        {
                            zipArchive.CreateEntry(string.Concat(entryName, Path.DirectorySeparatorChar));
                        }
                    }
                    else
                    {
                        ZipFile.CreateEntryFromFile(zipArchive, fileSystemInfo.FullName, entryName, compressionSettings);
                    }
                }

                if (includeBaseDirectory && empty)
                {
                    zipArchive.CreateEntry(string.Concat(directoryInfo.Name, Path.DirectorySeparatorChar));
                }
            }
        }
        private static bool IsDirectoryEmpty(DirectoryInfo directoryInfo)
        {
            bool empty = true;

            using (IEnumerator<FileSystemInfo> enumerator = directoryInfo.EnumerateFileSystemInfos("*", SearchOption.AllDirectories).GetEnumerator())
            {
                if (enumerator.MoveNext())
                {
                    empty = false;
                }
            }

            return empty;
        }

using (var archive = new ZipArchive(stream, ZipArchiveMode.Create, false, null))
    {
        foreach (var item in array)
        {
            using (var entry = archive.CreateEntry($"{item.Name}.reg-ext"))
            {
                XmlInOut<RegulationItem>.SaveToStream(entry.Open(), item);
            }
        }
    }

MemoryStream ms1 = new MemoryStream();

using (ZipArchive archive = new ZipArchive(ms1, ZipArchiveMode.Create, false, null))
{
	using (PdfFileSource fileSource = new PdfFileSource(File.OpenRead(documentToSplit)))
	{
		string splitDocumentName = "1st page.pdf";
		using (ZipArchiveEntry entry = archive.CreateEntry(splitDocumentName))
		{
			using (PdfStreamWriter writer = new PdfStreamWriter(entry.Open()))
			{
				PdfPageSource page = fileSource.Pages[0];
				writer.WritePage(page);
			}
		}
	}
}

File.WriteAllBytes("exported.zip", ms1.ToArray());

using (ZipArchive source = ZipFile.Open(sourceFileName, ZipArchiveMode.Read, null))
{
    foreach (ZipArchiveEntry entry in source.Entries)
    {
        string fullPath = Path.GetFullPath(Path.Combine(destinationDirectory, entry.FullName));

        if (Path.GetFileName(fullPath).Length != 0)
        {
            Directory.CreateDirectory(Path.GetDirectoryName(fullPath));
            // The boolean parameter determines whether an existing file that has the same name as the destination file should be overwritten
            entry.ExtractToFile(fullPath, true);
        }
    }
}