예제 #1
0
        public override Result decodeRow(int rowNumber, BitArray row, System.Collections.Hashtable hints)
        {
            // Compute this location once and reuse it on multiple implementations
            int[] startGuardPattern = UPCEANReader.findStartGuardPattern(row);
            int   size = readers.Count;

            for (int i = 0; i < size; i++)
            {
                UPCEANReader reader = (UPCEANReader)readers[i];
                Result       result;
                try
                {
                    result = reader.decodeRow(rowNumber, row, startGuardPattern, hints);
                }
                catch (ReaderException)
                {
                    continue;
                }
                // Special case: a 12-digit code encoded in UPC-A is identical to a "0"
                // followed by those 12 digits encoded as EAN-13. Each will recognize such a code,
                // UPC-A as a 12-digit string and EAN-13 as a 13-digit string starting with "0".
                // Individually these are correct and their readers will both read such a code
                // and correctly call it EAN-13, or UPC-A, respectively.
                //
                // In this case, if we've been looking for both types, we'd like to call it
                // a UPC-A code. But for efficiency we only run the EAN-13 decoder to also read
                // UPC-A. So we special case it here, and convert an EAN-13 result to a UPC-A
                // result if appropriate.
                if (result.BarcodeFormat.Equals(BarcodeFormat.EAN_13) && result.Text[0] == '0')
                {
                    return(new Result(result.Text.Substring(1), null, result.ResultPoints, BarcodeFormat.UPC_A));
                }
                return(result);
            }

            throw ReaderException.Instance;
        }