// create a barcode reader instance
IBarcodeReader reader = new BarcodeReader();
// load a bitmap
var barcodeBitmap = (Bitmap)Bitmap.LoadFrom("C:\\sample-barcode-image.png");
// detect and decode the barcode inside the bitmap
var result = reader.Decode(barcodeBitmap);
// do something with the result
if (result != null)
{
txtDecoderType.Text = result.BarcodeFormat.ToString();
txtDecoderContent.Text = result.Text;
}