解决了接口节点的参数共享，UI控件的Menu菜单事件穿透问题，同时优化了工作台画布流程相关事件的部分代码

Library/FlowNode/FlowCanvasDetails.cs

@@ -24,7 +24,6 @@ namespace Serein.Library
             Env = env;
         }
 
-
         public IFlowEnvironment Env { get; }
 
         /// <summary>
@@ -87,19 +86,17 @@ namespace Serein.Library
         [PropertyInfo(IsNotification = true)]
         private double _scaleY = 1;
 
-
         /// <summary>
-        /// 起始节点私有属性
+        /// 起始节点
         /// </summary>
-        private string _startNode;
+        [PropertyInfo]
+        private NodeModelBase _startNode;
 
     }
 
 
     public partial class FlowCanvasDetails
     {
-
-
     }
 
 

Library/FlowNode/ParameterDetails.cs

@@ -248,7 +248,8 @@ namespace Serein.Library
                 }
                 else
                 {
-                    inputParameter = context.GetFlowData(previousNode).Value; // 当前传递的数据
+                    var flowData = context.GetFlowData(previousNode);
+                    inputParameter = flowData.Value; // 当前传递的数据
                 }
             }
             else
@@ -259,7 +260,16 @@ namespace Serein.Library
                 }
                 if (ArgDataSourceType == ConnectionArgSourceType.GetOtherNodeData)
                 {
-                    inputParameter = context.GetFlowData(argSourceNodeModel).Value;
+                    var flowData = context.GetFlowData(argSourceNodeModel);
+                    if(flowData is null)
+                    {
+                        inputParameter = null;
+                    }
+                    else
+                    {
+
+                        inputParameter = flowData.Value;
+                    }
                 }
                 else if (ArgDataSourceType == ConnectionArgSourceType.GetOtherNodeDataOfInvoke)
                 {