Opens a zip file attached to an Acumatica document

ZipArchiveOpenBtn.cs

public PXAction<ARInvoice> OpenZip;

        [PXButton(CommitChanges = false)]
        [PXUIField(DisplayName = "Open .Zip", MapEnableRights = PXCacheRights.Update, MapViewRights = PXCacheRights.Update, Enabled = true)]
        protected virtual IEnumerable openZip(PXAdapter pxAdapter)
        {
            if(Base.Document.Current != null)
            {
                //Retrieves the sample .Zip file from the invoice
                Guid zipFile = PXNoteAttribute.GetFileNotes(Base.Document.Cache, Base.Document.Current).First();

                if(zipFile != null)
                {
                    UploadFileMaintenance uploadFileMaint = PXGraph.CreateInstance<UploadFileMaintenance>();

                    PX.SM.FileInfo fileInfo = uploadFileMaint.GetFile(zipFile);

                    if(fileInfo != null)
                    {
                        using (MemoryStream stream = new MemoryStream(fileInfo.BinData))
                        {
                            //Create new instance of ZipArchive to interact with .ZIP file
                            using (ZipArchive zip = ZipArchive.CreateFrom(stream, true))
                            {
                                //Iterate through all files and retrieve their ItemInfo
                                foreach(ZipArchive.ItemInfo info in zip.GetFiles())
                                {
                                    //Creates a stream from the specified file within the .ZIP file
                                    using (Stream fileStream = zip.OpenRead(info.Name))
                                    {
                                        using(MemoryStream innerStream = new MemoryStream())
                                        {
                                            fileStream.CopyTo(innerStream);

                                            //Create Acumatica file from .Zip file content
                                            fileInfo = new PX.SM.FileInfo(info.Name, null, innerStream.ToArray());

                                            //Saves file to Invoice
                                            if (uploadFileMaint.SaveFile(fileInfo, FileExistsAction.CreateVersion))
                                            {
                                                PXNoteAttribute.AttachFile(Base.Document.Cache, Base.Document.Current, fileInfo);
                                            }
                                        }
                                    }
                                }
                            }
                        }
                    }
                }
            }
            return pxAdapter.Get();
        }