Added ArchiveComment Property to ZipArchive

src/SharpCompress/Archives/Zip/ZipArchive.cs

@@ -23,6 +23,8 @@ public class ZipArchive : AbstractWritableArchive<ZipArchiveEntry, ZipVolume>
         /// </summary>
         public CompressionLevel DeflateCompressionLevel { get; set; }
 
+        public string ArchiveComment { get; private set; }
+
 #if !NO_FILE
 
         /// <summary>
@@ -154,6 +156,8 @@ protected override IEnumerable<ZipArchiveEntry> LoadEntries(IEnumerable<ZipVolum
                     {
                         case ZipHeaderType.DirectoryEntry:
                             {
+                                byte[] bytes = StringToByteArray((h as DirectoryEntryHeader).Comment);
+                                ArchiveComment = ReaderOptions.ArchiveEncoding.Decode(bytes); 
                                 yield return new ZipArchiveEntry(this,
                                                                  new SeekableZipFilePart(headerFactory,
                                                                                          h as DirectoryEntryHeader,
@@ -210,5 +214,14 @@ protected override IReader CreateReaderForSolidExtraction()
             stream.Position = 0;
             return ZipReader.Open(stream, ReaderOptions);
         }
+
+        private byte[] StringToByteArray(string hex)
+        {
+          int NumberChars = hex.Length;
+          byte[] bytes = new byte[NumberChars / 2];
+          for (int i = 0; i < NumberChars; i += 2)
+            bytes[i / 2] = Convert.ToByte(hex.Substring(i, 2), 16);
+          return bytes;
+        }
     }
 }

src/SharpCompress/Common/Zip/Headers/DirectoryEntryHeader.cs

@@ -73,6 +73,6 @@ internal override void Read(BinaryReader reader)
 
         public ushort DiskNumberStart { get; set; }
 
-        public string Comment { get; private set; }
+        public string Comment { get; set; }
     }
 }

src/SharpCompress/Common/Zip/SeekableZipHeaderFactory.cs

@@ -58,12 +58,25 @@ internal IEnumerable<DirectoryEntryHeader> ReadSeekableHeader(Stream stream)
                     yield break;
                 }
 
+                if (entry.Comment.Length != 0)
+                {
+                   directoryEntryHeader.Comment = ByteArrayToString(entry.Comment);
+                }
+
                 //entry could be zero bytes so we need to know that.
                 directoryEntryHeader.HasData = directoryEntryHeader.CompressedSize != 0;
                 yield return directoryEntryHeader;
             }
         }
 
+        internal string ByteArrayToString(byte[] ba)
+        {
+          StringBuilder hex = new StringBuilder(ba.Length * 2);
+          foreach (byte b in ba)
+            hex.AppendFormat("{0:x2}", b);
+          return hex.ToString();
+        }
+
         private static void SeekBackToHeader(Stream stream, BinaryReader reader, uint headerSignature)
         {
             long offset = 0;

tests/SharpCompress.Test/Zip/ZipArchiveTests.cs

@@ -11,7 +11,11 @@
 
 namespace SharpCompress.Test.Zip
 {
-    public class ZipArchiveTests : ArchiveTests
+  using Microsoft.VisualStudio.TestPlatform.ObjectModel;
+
+  using SharpCompress.Writers.Zip;
+
+  public class ZipArchiveTests : ArchiveTests
     {
         public ZipArchiveTests()
         {
@@ -461,5 +465,22 @@ public void TestSharpCompressWithEmptyStream()
                 }
             }
         }
+
+        [Fact]
+        public void ReadArchiveComment()
+        {
+          string expectedComment = "HelloWorld";
+          using (var streamArchive = ZipArchive.Create())
+          {
+            var zipStream = new MemoryStream();
+            streamArchive.AddEntry("Dummy", new MemoryStream());
+            streamArchive.SaveTo(zipStream, new ZipWriterOptions(CompressionType.Deflate) { ArchiveComment = expectedComment });
+            using (var openedArchive = ZipArchive.Open(zipStream))
+            {
+              var entries = openedArchive.Entries.ToList();
+              Assert.Equal(expectedComment, openedArchive.ArchiveComment);
+            }
+          }
+        }
     }
 }