添加项目文件。

zxing.core/xx/oned/MultiFormatUPCEANReader.cs

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+/*
+ * Copyright 2008 ZXing authors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+using System.Collections.Generic;
+using ZXing.Common;
+
+namespace ZXing.OneD
+{
+   /// <summary>
+   ///   <p>A reader that can read all available UPC/EAN formats. If a caller wants to try to
+   /// read all such formats, it is most efficient to use this implementation rather than invoke
+   /// individual readers.</p>
+   ///   <author>Sean Owen</author>
+   /// </summary>
+   public sealed class MultiFormatUPCEANReader : OneDReader
+   {
+      private readonly UPCEANReader[] readers;
+
+      /// <summary>
+      /// Initializes a new instance of the <see cref="MultiFormatUPCEANReader"/> class.
+      /// </summary>
+      /// <param name="hints">The hints.</param>
+      public MultiFormatUPCEANReader(IDictionary<DecodeHintType, object> hints)
+      {
+         var possibleFormats = hints == null || !hints.ContainsKey(DecodeHintType.POSSIBLE_FORMATS) ? null :
+             (IList<BarcodeFormat>)hints[DecodeHintType.POSSIBLE_FORMATS];
+         var readers = new List<UPCEANReader>();
+         if (possibleFormats != null)
+         {
+            if (possibleFormats.Contains(BarcodeFormat.EAN_13) || possibleFormats.Contains(BarcodeFormat.All_1D))
+            {
+               readers.Add(new EAN13Reader());
+            }
+            else if (possibleFormats.Contains(BarcodeFormat.UPC_A) || possibleFormats.Contains(BarcodeFormat.All_1D))
+            {
+               readers.Add(new UPCAReader());
+            }
+            if (possibleFormats.Contains(BarcodeFormat.EAN_8) || possibleFormats.Contains(BarcodeFormat.All_1D))
+            {
+               readers.Add(new EAN8Reader());
+            }
+            if (possibleFormats.Contains(BarcodeFormat.UPC_E) || possibleFormats.Contains(BarcodeFormat.All_1D))
+            {
+               readers.Add(new UPCEReader());
+            }
+         }
+         if (readers.Count == 0)
+         {
+            readers.Add(new EAN13Reader());
+            // UPC-A is covered by EAN-13
+            readers.Add(new EAN8Reader());
+            readers.Add(new UPCEReader());
+         }
+         this.readers = readers.ToArray();
+      }
+
+      /// <summary>
+      ///   <p>Attempts to decode a one-dimensional barcode format given a single row of
+      /// an image.</p>
+      /// </summary>
+      /// <param name="rowNumber">row number from top of the row</param>
+      /// <param name="row">the black/white pixel data of the row</param>
+      /// <param name="hints">decode hints</param>
+      /// <returns>
+      ///   <see cref="Result"/>containing encoded string and start/end of barcode or null if an error occurs or barcode cannot be found
+      /// </returns>
+      override public Result decodeRow(int rowNumber,
+                              BitArray row,
+                              IDictionary<DecodeHintType, object> hints)
+      {
+         // Compute this location once and reuse it on multiple implementations
+         int[] startGuardPattern = UPCEANReader.findStartGuardPattern(row);
+         if (startGuardPattern == null)
+            return null;
+
+         foreach (UPCEANReader reader in readers)
+         {
+            Result result = reader.decodeRow(rowNumber, row, startGuardPattern, hints);
+            if (result == null)
+               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.
+            //
+            // But, don't return UPC-A if UPC-A was not a requested format!
+            bool ean13MayBeUPCA =
+                result.BarcodeFormat == BarcodeFormat.EAN_13 &&
+                    result.Text[0] == '0';
+            var possibleFormats =
+                hints == null || !hints.ContainsKey(DecodeHintType.POSSIBLE_FORMATS) ? null : (IList<BarcodeFormat>)hints[DecodeHintType.POSSIBLE_FORMATS];
+            bool canReturnUPCA = possibleFormats == null || possibleFormats.Contains(BarcodeFormat.UPC_A) || possibleFormats.Contains(BarcodeFormat.All_1D);
+
+            if (ean13MayBeUPCA && canReturnUPCA)
+            {
+               // Transfer the metdata across
+               var resultUPCA = new Result(result.Text.Substring(1),
+                                              result.RawBytes,
+                                              result.ResultPoints,
+                                              BarcodeFormat.UPC_A);
+               resultUPCA.putAllMetadata(result.ResultMetadata);
+               return resultUPCA;
+            }
+            return result;
+         }
+
+         return null;
+      }
+
+      /// <summary>
+      /// Resets any internal state the implementation has after a decode, to prepare it
+      /// for reuse.
+      /// </summary>
+      public override void reset()
+      {
+         foreach (Reader reader in readers)
+         {
+            reader.reset();
+         }
+      }
+   }
+}