Barcode

// create readbarcodes object
var req = new ReadBarcodes()
    {
        // document
        Document = new Document()
        {
            DocData = File.ReadAllBytes("myPdf.pdf")
        },
        // action
        ReadBarcodeAction = new ReadBarcodeAction()
        {
        },
    };
    
// reading barcode from PDF
var res = Pdf4me.Instance.PdfAClient.ProtectAsync(req).GetAwaiter().GetResult();
            
// extracting the text and writing it to disk
string barcodeString = res.Barcodes.FirstOrDefault().BarcodeData;
File.WriteAllBytes("barcodeString.txt", barcodeString);

// reading barcode
var res = Pdf4me.Instance.BarcodeClient.ReadBarcodesByTypeAsync(File.ReadAllBytes("myPdf.pdf"), BarcodeType.All).ConfigureAwait(false).GetAwaiter().GetResult();

// extract the text and writing it to disk
string barcodeData = res.Barcodes.FirstOrDefault().BarcodeData;
File.WriteAllBytes("barcodeString.txt", barcodeData);

// creating barcode from text
var res = Pdf4me.Instance.BarcodeClient.CreateBarcodeByTypeAsync(BarcodType.QrCode, "example text", null).ConfigureAwait(false).GetAwaiter().GetResult();

// writing generated image to disk
using (var resfile = System.IO.File.OpenWrite('createBarcode.jpg'))
{
    res.Stream.CopyTo(resfile);
}

var splitByBarcodeReq = new SplitByBarcodeReq()
{
    Document = new Document
    {
        DocData = File.ReadAllBytes("mypdf.pdf")
    },
    SplitByBarcodeAction = new SplitByBarcodeAction
    {
        BarcodeString = "ara",
        BarcodeFilter = SplitByBarcodeActionBarcodeFilter.StartsWith,
        BarcodeType = SplitByBarcodeActionBarcodeType.Any,
        SplitBarcodePage = SplitByBarcodeActionSplitBarcodePage.Before
    }
};

var res = await Pdf4me.Instance.BarcodeClient.SplitByBarcodeAsync(splitByBarcodeReq).ConfigureAwait(false);

int i = 0;
foreach (var doc in res.SplittedDocuments)
    File.WriteAllBytes("pdf_" + i + ".pdf", doc.DocData);