Use the code example below as a guideline for writing PDF417 barcodes.

C# - Basic steps for writing PDF417 barcodes using Accusoft.BarcodeXpress.Net

using (BarcodeXpress bx = new BarcodeXpress("."))
using (WriterPDF417 pdf417Writer = new WriterPDF417(bx))
{
    // Set the text value
    pdf417Writer.BarcodeValue = "PDF417 Value";

    using (Bitmap bitmap = pdf417Writer.CreateBitmap())
    {
        bitmap.Save("testfile.bmp");
    }
}