MagicObject 添加快照的值获取

Author: JeffreySu

Senparc.CO2NET.MagicObject.Tests/MoTests.cs

@@ -43,6 +43,7 @@ public void Get_SingleProperty_NoChange()
             Assert.AreEqual("Alice", result.OldValue);
             Assert.AreEqual("Alice", result.NewValue);
             Assert.IsFalse(result.IsChanged);
+            Assert.IsFalse(result.HasShapshot);
         }
 
         [TestMethod]
@@ -107,20 +108,38 @@ public void SetProperties_BatchSetProperties()
         [TestMethod]
         public void TakeSnapshot_RestoreSnapshot()
         {
+            //_person = new Person { Name = "Alice", Age = 30 };
+
+            Assert.IsFalse(_mo.HasChanges());
+
             _mo.Set(p => p.Name, "Charlie");
+            Console.WriteLine(_mo.Get(z => z.Age).SnapshotValue);
+            Assert.IsFalse(_mo.Get(z => z.Age).HasShapshot);
+            Assert.IsNull(_mo.Get(z => z.Name).SnapshotValue);
+            Assert.AreEqual(0, _mo.Get(z => z.Age).SnapshotValue);//仍然会返回默认值
+            Assert.IsTrue(_mo.HasChanges());
+
             _mo.TakeSnapshot();
 
+            Assert.IsTrue(_mo.Get(z => z.Age).HasShapshot);
+            Assert.AreEqual( 30,_mo.Get(z => z.Age).SnapshotValue);
+
             _mo.Set(p => p.Name, "Dave");
             var resultBeforeRestore = _mo.Get(p => p.Name);
-            Assert.AreEqual("Charlie", resultBeforeRestore.OldValue);
+            Assert.AreEqual("Alice", resultBeforeRestore.OldValue);
+            Assert.AreEqual("Charlie", resultBeforeRestore.SnapshotValue);
             Assert.AreEqual("Dave", resultBeforeRestore.NewValue);
             Assert.IsTrue(resultBeforeRestore.IsChanged);
 
             _mo.RestoreSnapshot();
+            Assert.IsTrue(_mo.Get(z => z.Age).HasShapshot);//快照本身不会被清除
+
             var resultAfterRestore = _mo.Get(p => p.Name);
-            Assert.AreEqual("Charlie", resultAfterRestore.OldValue);
+            Assert.AreEqual("Alice", resultAfterRestore.OldValue);
+            Assert.AreEqual("Charlie", resultBeforeRestore.SnapshotValue);
             Assert.AreEqual("Charlie", resultAfterRestore.NewValue);
-            Assert.IsFalse(resultAfterRestore.IsChanged);
+            Assert.IsTrue(resultAfterRestore.IsChanged);
+            Assert.IsFalse(_mo.HasChanges());
         }
 
         [TestMethod]

Senparc.CO2NET.MagicObject/MO.cs

@@ -5,18 +5,6 @@
 
 namespace Senparc.CO2NET.MagicObject
 {
-    public class PropertyChangeResult<TValue>
-    {
-        public TValue OldValue { get; set; }
-        public TValue NewValue { get; set; }
-        public bool IsChanged { get; set; }
-
-        public override string ToString()
-        {
-            return IsChanged ? $"{OldValue} -> {NewValue}" : NewValue?.ToString();
-        }
-    }
-
     public class MO<T>
     {
         private T OriginalObject { get; set; }
@@ -77,14 +65,20 @@ public PropertyChangeResult<TValue> Get<TValue>(Expression<Func<T, TValue>> expr
         {
             if (expression.Body is MemberExpression memberExpression && memberExpression.Member is PropertyInfo propertyInfo)
             {
-                var originalValue = (TValue)propertyInfo.GetValue(_snapshot != null ? _snapshot : OriginalObject);
+                var hasSnapshot = _snapshot != null;
+
+                var originalValue = (TValue)propertyInfo.GetValue(OriginalObject);
+
+                TValue? snapshptValue = hasSnapshot ? (TValue?)propertyInfo.GetValue(_snapshot) : default;
                 var newValue = (TValue)propertyInfo.GetValue(Object);
 
                 return new PropertyChangeResult<TValue>
                 {
                     OldValue = originalValue,
+                    SnapshotValue = snapshptValue,
                     NewValue = newValue,
-                    IsChanged = !Equals(originalValue, newValue)
+                    IsChanged = /*hasSnapshot ? Equals(snapshptValue, newValue) :*/ !Equals(originalValue, newValue),
+                    HasShapshot = hasSnapshot
                 };
             }
             else

Senparc.CO2NET.MagicObject/PropertyChangeResult.cs

@@ -0,0 +1,24 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace Senparc.CO2NET.MagicObject
+{
+    public class PropertyChangeResult<TValue>
+    {
+        public TValue OldValue { get; set; }
+        public TValue NewValue { get; set; }
+        public TValue? SnapshotValue { get; set; }
+        public bool IsChanged { get; set; }
+        public bool HasShapshot { get; set; }
+
+
+        public override string ToString()
+        {
+            return IsChanged ? $"{OldValue} -> {NewValue}" : NewValue?.ToString();
+        }
+    }
+
+}