序列化bug修复，近期主要修复bug为主

AIStudio.Wpf.DiagramDesigner/Models/Serializables/DesignerItemBase.cs

@@ -107,18 +107,45 @@ namespace AIStudio.Wpf.DiagramDesigner
             get; set;
         }
 
-        [XmlAttribute]
+        [XmlIgnore]
         public CornerRadius CornerRadius
         {
             get; set;
         }
 
-        [XmlAttribute]
+        [JsonIgnore]
+        [XmlElement("CornerRadius")]
+        public string XmlCornerRadius
+        {
+            get
+            {
+                return SerializeHelper.SerializeCornerRadius(CornerRadius);
+            }
+            set
+            {
+                CornerRadius = SerializeHelper.DeserializeCornerRadius(value);
+            }
+        }
+
+        [XmlIgnore]
         public Thickness BorderThickness
         {
             get; set;
         }
 
+        [JsonIgnore]
+        [XmlElement("BorderThickness")]
+        public string XmlBorderThickness
+        {
+            get
+            {
+                return SerializeHelper.SerializeThickness(BorderThickness);
+            }
+            set
+            {
+                BorderThickness = SerializeHelper.DeserializeThickness(value);
+            }
+        }
 
         [XmlArray]
         public List<FullyCreatedConnectorInfoItem> Connectors

AIStudio.Wpf.DiagramDesigner/ViewModels/BaseViewModel/DiagramViewModel.cs

@@ -1051,6 +1051,8 @@ namespace AIStudio.Wpf.DiagramDesigner
             Mediator.Instance.Register(this);
             Items.CollectionChanged += Items_CollectionChanged;
             var zoomValueChangedSubscription = WhenPropertyChanged.Where(o => o.ToString() == nameof(ZoomValue)).Throttle(TimeSpan.FromMilliseconds(100)).Subscribe(OnZoomValueChanged);//Sample
+           
+            BuildMenuOptions();
         }
         public DiagramViewModel(DiagramItem diagramItem) : this()
         {
@@ -1066,11 +1068,10 @@ namespace AIStudio.Wpf.DiagramDesigner
             GridColor = diagramItem.GridColor;
             AllowDrop = diagramItem.AllowDrop;
 
-            Init();
-            BuildMenuOptions();
+            Init(true);
         }
 
-        public virtual void Init()
+        public virtual void Init(bool initNew)
         {
             DoCommandManager.Init();
         }

AIStudio.Wpf.DiagramDesigner/ViewModels/IDiagramViewModel.cs

@@ -333,7 +333,7 @@ namespace AIStudio.Wpf.DiagramDesigner
         }
         #endregion
 
-        void Init();
+        void Init(bool initNew);
 
         void Add(object parameter);