Issue-956 dxfclasses writer fix

README.md

@@ -27,7 +27,7 @@ AC1015 |    :heavy_check_mark:    |   :heavy_check_mark:     |    :heavy_check_m
 AC1018 |    :heavy_check_mark:    |   :heavy_check_mark:     |    :heavy_check_mark:    |    :heavy_check_mark:    |
 AC1021 |    :heavy_check_mark:    |   :heavy_check_mark:     |    :heavy_check_mark:    |    :x:                   |
 AC1024 |    :heavy_check_mark:    |   :heavy_check_mark:     |    :heavy_check_mark:    |    :heavy_check_mark:    |
-AC1027 |    :heavy_check_mark:    |   :heavy_check_mark:     |    :heavy_check_mark:    |    :heavy_check_mark:                   |
+AC1027 |    :heavy_check_mark:    |   :heavy_check_mark:     |    :heavy_check_mark:    |    :heavy_check_mark:    |
 AC1032 |    :heavy_check_mark:    |   :heavy_check_mark:     |    :heavy_check_mark:    |    :heavy_check_mark:    |
 
 Code Example
@@ -40,7 +40,7 @@ public static void Main()
 	CadDocument doc = DwgReader.Read(path, onNotification);
 }
 
-// Process a notification form the reader
+// Process a notification from the reader
 private static void onNotification(object sender, NotificationEventArgs e)
 {
 	Console.WriteLine(e.Message);

src/ACadSharp.Tests/IO/DXF/DxfWriterSingleObjectTests.cs

@@ -9,6 +9,13 @@ public class DxfWriterSingleObjectTests : WriterSingleObjectTests
 	{
 		public DxfWriterSingleObjectTests(ITestOutputHelper output) : base(output) { }
 
+		[Theory()]
+		[MemberData(nameof(Data))]
+		public void WriteCasesAC1015(SingleCaseGenerator data)
+		{
+			this.writeDxfFile(data, ACadVersion.AC1015);
+		}
+
 		[Theory()]
 		[MemberData(nameof(Data))]
 		public void WriteCasesAC1018(SingleCaseGenerator data)

src/ACadSharp/ACadSharp.csproj

@@ -17,7 +17,7 @@
 	<PropertyGroup>
 		<GenerateDocumentationFile>true</GenerateDocumentationFile>
 		<PackageReadmeFile>README.md</PackageReadmeFile>
-		<Version>3.4.1</Version>
+		<Version>3.4.2</Version>
 		<PackageOutputPath>../nupkg</PackageOutputPath>
 		<SignAssembly>True</SignAssembly>
 		<AssemblyOriginatorKeyFile>../ACadSharp.snk</AssemblyOriginatorKeyFile>

src/ACadSharp/Classes/DxfClass.cs

@@ -43,12 +43,47 @@ public class DxfClass
 		/// If 0, instances may appear only in the OBJECTS section
 		/// </summary>
 		[DxfCodeValue(281)]
-		public bool IsAnEntity { get; set; }
+		public bool IsAnEntity
+		{
+			get => this._isAnEntity;
+			set
+			{
+				if (value)
+				{
+					this._itemClassId = 0x1F2;
+				}
+				else
+				{
+					this._itemClassId = 0x1F3;
+				}
+
+				this._isAnEntity = value;
+			}
+		}
 
 		/// <summary>
 		/// Item class id.
 		/// </summary>
-		public short ItemClassId { get; internal set; }
+		/// <remarks>
+		/// Only effective for dwg.
+		/// </remarks>
+		public short ItemClassId
+		{
+			get => this._itemClassId;
+			set
+			{
+				if (value == 0x1F2)
+				{
+					this._isAnEntity = true;
+				}
+				else
+				{
+					this._isAnEntity = false;
+				}
+
+				this._itemClassId = value;
+			}
+		}
 
 		/// <summary>
 		/// Proxy capabilities flag.
@@ -66,10 +101,14 @@ public class DxfClass
 
 		internal short MaintenanceVersion { get; set; }
 
+		private bool _isAnEntity;
+
+		private short _itemClassId;
+
 		/// <inheritdoc/>
 		public override string ToString()
 		{
-			return $"{DxfName}:{ClassNumber}";
+			return $"{this.DxfName}:{this.ClassNumber}";
 		}
 	}
 }

src/ACadSharp/Classes/DxfClassCollection.cs

@@ -494,7 +494,6 @@ public static void UpdateDxfClasses(CadDocument doc)
 				MaintenanceVersion = 0,
 				ProxyFlags = ProxyFlags.None,
 				WasZombie = false,
-				IsAnEntity = false,
 			});
 
 			//AcDbMLeaderObjectContextData

src/ACadSharp/IO/DWG/DwgStreamReaders/DwgClassesReader.cs

@@ -95,18 +95,6 @@ public DxfClassCollection Read()
 				dxfClass.WasZombie = this._sreader.ReadBit();
 				//BS : itemclassid -- 0x1F2 for classes which produce entities, 0x1F3 for classes which produce objects.
 				dxfClass.ItemClassId = this._sreader.ReadBitShort();
-				if (dxfClass.ItemClassId == 0x1F2)
-				{
-					dxfClass.IsAnEntity = true;
-				}
-				else if (dxfClass.ItemClassId == 0x1F3)
-				{
-					dxfClass.IsAnEntity = false;
-				}
-				else
-				{
-					this.notify($"Invalid DxfClass id value: {dxfClass.ItemClassId} for {dxfClass.CppClassName}", NotificationType.Warning);
-				}
 
 				if (this.R2004Plus)
 				{

src/ACadSharp/IO/DXF/DxfStreamWriter/DxfClassesSectionWriter.cs

@@ -16,7 +16,12 @@ protected override void writeSection()
 				this._writer.Write(2, c.CppClassName);
 				this._writer.Write(3, c.ApplicationName);
 				this._writer.Write(90, (int)c.ProxyFlags);
-				this._writer.Write(91, c.InstanceCount);
+
+				if (this.Version > ACadVersion.AC1015)
+				{
+					this._writer.Write(91, c.InstanceCount);
+				}
+
 				this._writer.Write(280, c.WasZombie);
 				this._writer.Write(281, c.IsAnEntity);
 			}