C# BitArray.isRange方法代码示例

      /// <summary>
      ///   <p>Like decodeRow(int, BitArray, java.util.Map), but
      /// allows caller to inform method about where the UPC/EAN start pattern is
      /// found. This allows this to be computed once and reused across many implementations.</p>
      /// </summary>
      /// <param name="rowNumber">row index into the image</param>
      /// <param name="row">encoding of the row of the barcode image</param>
      /// <param name="startGuardRange">start/end column where the opening start pattern was found</param>
      /// <param name="hints">optional hints that influence decoding</param>
      /// <returns><see cref="Result"/> encapsulating the result of decoding a barcode in the row</returns>
      virtual public Result decodeRow(int rowNumber,
                              BitArray row,
                              int[] startGuardRange,
                              IDictionary<DecodeHintType, object> hints)
      {
         var resultPointCallback = hints == null || !hints.ContainsKey(DecodeHintType.NEED_RESULT_POINT_CALLBACK) ? null :
             (ResultPointCallback)hints[DecodeHintType.NEED_RESULT_POINT_CALLBACK];

         if (resultPointCallback != null)
         {
            resultPointCallback(new ResultPoint(
                (startGuardRange[0] + startGuardRange[1]) / 2.0f, rowNumber
            ));
         }

         var result = decodeRowStringBuffer;
         result.Length = 0;
         var endStart = decodeMiddle(row, startGuardRange, result);
         if (endStart < 0)
            return null;

         if (resultPointCallback != null)
         {
            resultPointCallback(new ResultPoint(
                endStart, rowNumber
            ));
         }

         var endRange = decodeEnd(row, endStart);
         if (endRange == null)
            return null;

         if (resultPointCallback != null)
         {
            resultPointCallback(new ResultPoint(
                (endRange[0] + endRange[1]) / 2.0f, rowNumber
            ));
         }


         // Make sure there is a quiet zone at least as big as the end pattern after the barcode. The
         // spec might want more whitespace, but in practice this is the maximum we can count on.
         var end = endRange[1];
         var quietEnd = end + (end - endRange[0]);
         if (quietEnd >= row.Size || !row.isRange(end, quietEnd, false))
         {
            return null;
         }

         var resultString = result.ToString();
         // UPC/EAN should never be less than 8 chars anyway
         if (resultString.Length < 8)
         {
            return null;
         }
         if (!checkChecksum(resultString))
         {
            return null;
         }

         var left = (startGuardRange[1] + startGuardRange[0]) / 2.0f;
         var right = (endRange[1] + endRange[0]) / 2.0f;
         var format = BarcodeFormat;
         var decodeResult = new Result(resultString,
                                          null, // no natural byte representation for these barcodes
                                          new ResultPoint[]
                                             {
                                                new ResultPoint(left, rowNumber),
                                                new ResultPoint(right, rowNumber)
                                             },
                                          format);

         var extensionResult = extensionReader.decodeRow(rowNumber, row, endRange[1]);
         if (extensionResult != null)
         {
            decodeResult.putMetadata(ResultMetadataType.UPC_EAN_EXTENSION, extensionResult.Text);
            decodeResult.putAllMetadata(extensionResult.ResultMetadata);
            decodeResult.addResultPoints(extensionResult.ResultPoints);
            int extensionLength = extensionResult.Text.Length;
            int[] allowedExtensions = hints != null && hints.ContainsKey(DecodeHintType.ALLOWED_EAN_EXTENSIONS) ? 
               (int[]) hints[DecodeHintType.ALLOWED_EAN_EXTENSIONS] : null;
            if (allowedExtensions != null)
            {
               bool valid = false;
               foreach (int length in allowedExtensions)
               {
                  if (extensionLength == length)
                  {
                     valid = true;
                     break;
//.........这里部分代码省略.........

      private int[] findEndPattern(BitArray row, int rowOffset, int[] counters)
      {
         const int patternLength = 3;

         int width = row.Size;

         int counterPosition = 0;
         int patternStart = rowOffset;
         bool isWhite = false;

         counters[0] = 0;
         counters[1] = 0;
         counters[2] = 0;
         for (int i = rowOffset; i < width; i++)
         {
            if (row[i] ^ isWhite)
            {
               counters[counterPosition]++;
            }
            else
            {
               if (counterPosition == patternLength - 1)
               {
                  var factorNarrowToWide = ((float)counters[1]) / ((float)counters[0]);
                  if (factorNarrowToWide >= 1.5 && factorNarrowToWide <= 5)
                  {
                     if (toPattern(counters, patternLength) == END_ENCODING)
                     {
                        // Look for whitespace after end pattern, >= 50% of width of end pattern
                        var minEndOfWhite = Math.Min(row.Size - 1, i + ((i - patternStart) >> 1));
                        if (row.isRange(i, minEndOfWhite, false))
                        {
                           return new int[] {patternStart, i};
                        }
                     }
                  }
                  return null;
               }
               counterPosition++;
               counters[counterPosition] = 1;
               isWhite = !isWhite;
            }
         }
         return null;
      }

 internal static int[] findStartGuardPattern(BitArray row)
 {
    bool foundStart = false;
    int[] startRange = null;
    int nextStart = 0;
    int[] counters = new int[START_END_PATTERN.Length];
    while (!foundStart)
    {
       for (int idx = 0; idx < START_END_PATTERN.Length; idx++)
          counters[idx] = 0;
       startRange = findGuardPattern(row, nextStart, false, START_END_PATTERN, counters);
       if (startRange == null)
          return null;
       int start = startRange[0];
       nextStart = startRange[1];
       // Make sure there is a quiet zone at least as big as the start pattern before the barcode.
       // If this check would run off the left edge of the image, do not accept this barcode,
       // as it is very likely to be a false positive.
       int quietStart = start - (nextStart - start);
       if (quietStart >= 0)
       {
          foundStart = row.isRange(quietStart, start, false);
       }
    }
    return startRange;
 }

      private int[] findStartPattern(BitArray row, int[] counters)
      {
         const int patternLength = 2;

         int width = row.Size;
         int rowOffset = row.getNextSet(0);

         int counterPosition = 0;
         int patternStart = rowOffset;
         bool isWhite = false;

         counters[0] = 0;
         counters[1] = 0;
         for (int i = rowOffset; i < width; i++)
         {
            if (row[i] ^ isWhite)
            {
               counters[counterPosition]++;
            }
            else
            {
               if (counterPosition == patternLength - 1)
               {
                  // narrow and wide areas should be as near as possible to factor 2
                  // lets say we will check 1.5 <= factor <= 5
                  var factorNarrowToWide = ((float)counters[0]) / ((float)counters[1]);
                  if (factorNarrowToWide >= 1.5 && factorNarrowToWide <= 5)
                  {
                     calculateAverageCounterWidth(counters, patternLength);
                     if (toPattern(counters, patternLength) == START_ENCODING)
                     {
                        // Look for whitespace before start pattern, >= 50% of width of start pattern
                        if (row.isRange(Math.Max(0, patternStart - ((i - patternStart) >> 1)), patternStart, false))
                        {
                           return new int[] {patternStart, i};
                        }
                     }
                  }
                  patternStart += counters[0] + counters[1];
                  Array.Copy(counters, 2, counters, 0, patternLength - 2);
                  counters[patternLength - 2] = 0;
                  counters[patternLength - 1] = 0;
                  counterPosition--;
               }
               else
               {
                  counterPosition++;
               }
               counters[counterPosition] = 1;
               isWhite = !isWhite;
            }
         }
         return null;
      }

      private static int[] findAsteriskPattern(BitArray row, int[] counters)
      {
         int width = row.Size;
         int rowOffset = row.getNextSet(0);

         int counterPosition = 0;
         int patternStart = rowOffset;
         bool isWhite = false;
         int patternLength = counters.Length;

         for (int i = rowOffset; i < width; i++)
         {
            if (row[i] ^ isWhite)
            {
               counters[counterPosition]++;
            }
            else
            {
               if (counterPosition == patternLength - 1)
               {
                  if (toNarrowWidePattern(counters) == ASTERISK_ENCODING)
                  {
                     // Look for whitespace before start pattern, >= 50% of width of start pattern
                     if (row.isRange(Math.Max(0, patternStart - ((i - patternStart) >> 1)), patternStart, false))
                     {
                        return new int[] { patternStart, i };
                     }
                  }
                  patternStart += counters[0] + counters[1];
                  Array.Copy(counters, 2, counters, 0, patternLength - 2);
                  counters[patternLength - 2] = 0;
                  counters[patternLength - 1] = 0;
                  counterPosition--;
               }
               else
               {
                  counterPosition++;
               }
               counters[counterPosition] = 1;
               isWhite = !isWhite;
            }
         }
         return null;
      }

//.........这里部分代码省略.........
                     {
                        lastCharacterWasPrintable = false;
                     }
                     switch (code)
                     {
                        case CODE_FNC_1:
                           // do nothing?
                           break;
                        case CODE_CODE_A:
                           codeSet = CODE_CODE_A;
                           break;
                        case CODE_CODE_B:
                           codeSet = CODE_CODE_B;
                           break;
                        case CODE_STOP:
                           done = true;
                           break;
                     }
                  }
                  break;
            }

            // Unshift back to another code set if we were shifted
            if (unshift)
            {
               codeSet = codeSet == CODE_CODE_A ? CODE_CODE_B : CODE_CODE_A;
            }

         }

         // Check for ample whitespace following pattern, but, to do this we first need to remember that
         // we fudged decoding CODE_STOP since it actually has 7 bars, not 6. There is a black bar left
         // to read off. Would be slightly better to properly read. Here we just skip it:
         nextStart = row.getNextUnset(nextStart);
         if (!row.isRange(nextStart,
                          Math.Min(row.Size, nextStart + (nextStart - lastStart) / 2),
                          false))
         {
            return null;
         }

         // Pull out from sum the value of the penultimate check code
         checksumTotal -= multiplier * lastCode;
         // lastCode is the checksum then:
         if (checksumTotal % 103 != lastCode)
         {
            return null;
         }

         // Need to pull out the check digits from string
         int resultLength = result.Length;
         if (resultLength == 0)
         {
            // false positive
            return null;
         }

         // Only bother if the result had at least one character, and if the checksum digit happened to
         // be a printable character. If it was just interpreted as a control code, nothing to remove.
         if (resultLength > 0 && lastCharacterWasPrintable)
         {
            if (codeSet == CODE_CODE_C)
            {
               result.Remove(resultLength - 2, 2);
            }
            else
            {
               result.Remove(resultLength - 1, 1);
            }
         }

         float left = (startPatternInfo[1] + startPatternInfo[0]) / 2.0f;
         float right = (nextStart + lastStart) / 2.0f;

         var resultPointCallback = hints == null || !hints.ContainsKey(DecodeHintType.NEED_RESULT_POINT_CALLBACK)
                             ? null
                             : (ResultPointCallback)hints[DecodeHintType.NEED_RESULT_POINT_CALLBACK];
         if (resultPointCallback != null)
         {
            resultPointCallback(new ResultPoint(left, rowNumber));
            resultPointCallback(new ResultPoint(right, rowNumber));
         }

         int rawCodesSize = rawCodes.Count;
         var rawBytes = new byte[rawCodesSize];
         for (int i = 0; i < rawCodesSize; i++)
         {
            rawBytes[i] = rawCodes[i];
         }

         return new Result(
            result.ToString(),
            rawBytes,
            new []
               {
                  new ResultPoint(left, rowNumber),
                  new ResultPoint(right, rowNumber)
               },
            BarcodeFormat.CODE_128);
      }

      private static int[] findStartPattern(BitArray row)
      {
         int width = row.Size;
         int rowOffset = row.getNextSet(0);

         int counterPosition = 0;
         int[] counters = new int[6];
         int patternStart = rowOffset;
         bool isWhite = false;
         int patternLength = counters.Length;

         for (int i = rowOffset; i < width; i++)
         {
            if (row[i] ^ isWhite)
            {
               counters[counterPosition]++;
            }
            else
            {
               if (counterPosition == patternLength - 1)
               {
                  int bestVariance = MAX_AVG_VARIANCE;
                  int bestMatch = -1;
                  for (int startCode = CODE_START_A; startCode <= CODE_START_C; startCode++)
                  {
                     int variance = patternMatchVariance(counters, CODE_PATTERNS[startCode],
                         MAX_INDIVIDUAL_VARIANCE);
                     if (variance < bestVariance)
                     {
                        bestVariance = variance;
                        bestMatch = startCode;
                     }
                  }
                  if (bestMatch >= 0)
                  {
                     // Look for whitespace before start pattern, >= 50% of width of start pattern
                     if (row.isRange(Math.Max(0, patternStart - (i - patternStart) / 2), patternStart,
                         false))
                     {
                        return new int[] { patternStart, i, bestMatch };
                     }
                  }
                  patternStart += counters[0] + counters[1];
                  Array.Copy(counters, 2, counters, 0, patternLength - 2);
                  counters[patternLength - 2] = 0;
                  counters[patternLength - 1] = 0;
                  counterPosition--;
               }
               else
               {
                  counterPosition++;
               }
               counters[counterPosition] = 1;
               isWhite = !isWhite;
            }
         }
         return null;
      }

      /// <summary>
      /// <p>Like decodeRow(int, BitArray, java.util.Map), but
      /// allows caller to inform method about where the UPC/EAN start pattern is
      /// found. This allows this to be computed once and reused across many implementations.</p>
      /// </summary>
      virtual public Result decodeRow(int rowNumber,
                              BitArray row,
                              int[] startGuardRange,
                              IDictionary<DecodeHintType, object> hints)
      {

         ResultPointCallback resultPointCallback = hints == null || !hints.ContainsKey(DecodeHintType.NEED_RESULT_POINT_CALLBACK) ? null :
             (ResultPointCallback)hints[DecodeHintType.NEED_RESULT_POINT_CALLBACK];

         if (resultPointCallback != null)
         {
            resultPointCallback(new ResultPoint(
                (startGuardRange[0] + startGuardRange[1]) / 2.0f, rowNumber
            ));
         }

         StringBuilder result = decodeRowStringBuffer;
         result.Length = 0;
         int endStart = decodeMiddle(row, startGuardRange, result);
         if (endStart < 0)
            return null;

         if (resultPointCallback != null)
         {
            resultPointCallback(new ResultPoint(
                endStart, rowNumber
            ));
         }

         int[] endRange = decodeEnd(row, endStart);
         if (endRange == null)
            return null;

         if (resultPointCallback != null)
         {
            resultPointCallback(new ResultPoint(
                (endRange[0] + endRange[1]) / 2.0f, rowNumber
            ));
         }


         // Make sure there is a quiet zone at least as big as the end pattern after the barcode. The
         // spec might want more whitespace, but in practice this is the maximum we can count on.
         int end = endRange[1];
         int quietEnd = end + (end - endRange[0]);
         if (quietEnd >= row.Size || !row.isRange(end, quietEnd, false))
         {
            return null;
         }

         String resultString = result.ToString();
         if (!checkChecksum(resultString))
         {
            return null;
         }

         float left = (startGuardRange[1] + startGuardRange[0]) / 2.0f;
         float right = (endRange[1] + endRange[0]) / 2.0f;
         BarcodeFormat format = BarcodeFormat;
         Result decodeResult = new Result(resultString,
                                          null, // no natural byte representation for these barcodes
                                          new ResultPoint[]
                                             {
                                                new ResultPoint(left, rowNumber),
                                                new ResultPoint(right, rowNumber)
                                             },
                                          format);

         Result extensionResult = extensionReader.decodeRow(rowNumber, row, endRange[1]);
         if (extensionResult != null)
         {
            decodeResult.putMetadata(ResultMetadataType.UPC_EAN_EXTENSION, extensionResult.Text);
            decodeResult.putAllMetadata(extensionResult.ResultMetadata);
            decodeResult.addResultPoints(extensionResult.ResultPoints);
         }

         if (format == BarcodeFormat.EAN_13 || format == BarcodeFormat.UPC_A)
         {
            String countryID = eanManSupport.lookupCountryIdentifier(resultString);
            if (countryID != null)
            {
               decodeResult.putMetadata(ResultMetadataType.POSSIBLE_COUNTRY, countryID);
            }
         }

         return decodeResult;
      }