Merge pull request #415 from scamille/fb-fixClassUint32

Fix ReadClass for UInt32
S7NetPlus · Dec 10, 2022 · 6aa0133 · 6aa0133
2 parents 3833d29 + 868e719
commit 6aa0133
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Showing 2 changed files with 24 additions and 11 deletions.
diff --git a/S7.Net.UnitTest/TypeTests/ClassTests.cs b/S7.Net.UnitTest/TypeTests/ClassTests.cs
@@ -17,6 +17,19 @@ public void GetClassSizeTest()
             Assert.AreEqual(Class.GetClassSize(new TestClassUnevenSize(3, 17)), 10);
         }
 
+        /// <summary>
+        /// Ensure Uint32 is correctly parsed through ReadClass functions. Adresses issue https://github.com/S7NetPlus/s7netplus/issues/414
+        /// </summary>
+        [TestMethod]
+        public void TestUint32Read()
+        {
+            var result = new TestUint32();
+            var data = new byte[4] { 0, 0, 0, 5 };
+            var bytesRead = Class.FromBytes(result, data);
+            Assert.AreEqual(bytesRead, data.Length);
+            Assert.AreEqual(5u, result.Value1);
+        }
+
         private class TestClassUnevenSize
         {
             public bool Bool { get; set; }
@@ -29,5 +42,10 @@ public TestClassUnevenSize(int byteCount, int bitCount)
                 Bools = new bool[bitCount];
             }
         }
+
+        private class TestUint32
+        {
+            public uint Value1 { get; set; }
+        }
     }
 }
diff --git a/S7.Net/Types/Class.cs b/S7.Net/Types/Class.cs
@@ -148,22 +148,17 @@ public static double GetClassSize(object instance, double numBytes = 0.0, bool i
                     break;
                 case "Int32":
                     IncrementToEven(ref numBytes);
-                    // hier auswerten
-                    uint sourceUInt = DWord.FromBytes(bytes[(int)numBytes + 3],
-                                                                       bytes[(int)numBytes + 2],
-                                                                       bytes[(int)numBytes + 1],
-                                                                       bytes[(int)numBytes + 0]);
+                    var wordBuffer = new byte[4];
+                    Array.Copy(bytes, (int)numBytes, wordBuffer, 0, wordBuffer.Length);
+                    uint sourceUInt = DWord.FromByteArray(wordBuffer);
                     value = sourceUInt.ConvertToInt();
                     numBytes += 4;
                     break;
                 case "UInt32":
                     IncrementToEven(ref numBytes);
-                    // hier auswerten
-                    value = DWord.FromBytes(
-                        bytes[(int)numBytes],
-                        bytes[(int)numBytes + 1],
-                        bytes[(int)numBytes + 2],
-                        bytes[(int)numBytes + 3]);
+                    var wordBuffer2 = new byte[4];
+                    Array.Copy(bytes, (int)numBytes, wordBuffer2, 0, wordBuffer2.Length);
+                    value = DWord.FromByteArray(wordBuffer2);
                     numBytes += 4;
                     break;
                 case "Single":