UNZIP EN VB.NET

Public Sub ExtractArchive(ByVal zipFilename As String, ByVal ExtractDir As String)
        Dim Redo As Integer = 1
        Dim MyZipInputStream As ZipInputStream
        Dim MyFileStream As FileStream
        MyZipInputStream = New ZipInputStream(New FileStream(zipFilename, FileMode.Open, FileAccess.Read))
        Dim MyZipEntry As ZipEntry = MyZipInputStream.GetNextEntry
        Directory.CreateDirectory(ExtractDir)
        While Not MyZipEntry Is Nothing
            If (MyZipEntry.IsDirectory) Then
                Directory.CreateDirectory(ExtractDir & "\" & MyZipEntry.Name)
            Else
                If Not Directory.Exists(ExtractDir & "\" & Path.GetDirectoryName(MyZipEntry.Name)) Then
                    Directory.CreateDirectory(ExtractDir & "\" & Path.GetDirectoryName(MyZipEntry.Name))
                End If
                MyFileStream = New FileStream(ExtractDir & "\" & MyZipEntry.Name, FileMode.OpenOrCreate, FileAccess.Write)
                Dim count As Integer
                Dim buffer(4096) As Byte
                count = MyZipInputStream.Read(buffer, 0, 4096)
                While count > 0
                    MyFileStream.Write(buffer, 0, count)
                    count = MyZipInputStream.Read(buffer, 0, 4096)
                End While
                MyFileStream.Close()
            End If
            Try
                MyZipEntry = MyZipInputStream.GetNextEntry
            Catch ex As Exception
                MyZipEntry = Nothing
            End Try
        End While
        If Not (MyZipInputStream Is Nothing) Then MyZipInputStream.Close()
        If Not (MyFileStream Is Nothing) Then MyFileStream.Close()
    End Sub