重新设计了创建连线时的逻辑，能够预览连接成功后的外观样式

Serein.Workbench.Avalonia/Custom/Node/Views/NodeControlBase.cs

@@ -0,0 +1,57 @@
+using Avalonia.Controls;
+using Avalonia.Data;
+using Avalonia.Media;
+using Serein.Library;
+using Serein.Workbench.Avalonia.Api;
+using Serein.Workbench.Avalonia.Custom.Views;
+using Serein.Workbench.Avalonia.Model;
+using Serein.Workbench.Avalonia.ViewModels;
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace Serein.Workbench.Avalonia.Custom.Node.Views
+{
+    public class NodeControlBase : UserControl
+    {
+        protected NodeControlBase()
+        {
+            this.Background = Brushes.Transparent;
+        }
+
+        /// <summary>
+        /// 放置在某个节点容器中
+        /// </summary>
+        public void PlaceToContainer(INodeContainerControl nodeContainerControl)
+        {
+            //this.nodeContainerControl = nodeContainerControl;
+            //NodeCanvas.Children.Remove(this); // 临时从画布上移除
+            //var result = nodeContainerControl.PlaceNode(this);
+            //if (!result) // 检查是否放置成功，如果不成功，需要重新添加回来
+            //{
+            //    NodeCanvas.Children.Add(this); // 从画布上移除
+
+            //}
+        }
+
+        /// <summary>
+        /// 从某个节点容器取出
+        /// </summary>
+        public void TakeOutContainer()
+        {
+            //var result = nodeContainerControl.TakeOutNode(this); // 从控件取出
+            //if (result) // 移除成功时才添加到画布上
+            //{
+            //    NodeCanvas.Children.Add(this); // 重新添加到画布上
+            //    if (nodeContainerControl is NodeControlBase containerControl)
+            //    {
+            //        NodeModel.Position.X = NodeModel.Position.X + containerControl.Width + 10;
+            //        NodeModel.Position.Y = NodeModel.Position.Y;
+            //    }
+            //}
+
+        }
+    }
+}