title: get barcode reader value form background monitoring
body: <p>I want to create an accounting program with c# language.
  I want to use a barcode reader for searching  products in shop (this is optional for my program)
  Now, in main form if seller uses a barcode reader get barcode value for handle method or event;
  How can I get barcode value in background of Form (without text box) for handle method or event ?</p>
  
  <p>Note: My barcode reader is HID (USB interface)</p>