fix：

Views/UserControl/Viewport3D.xaml.cs

@@ -601,23 +601,23 @@ public partial class Viewport3D
         var mousePosition = e.GetPosition(Viewport3Dx);
         var hits = Viewport3Dx.FindHits(mousePosition);
         // 如果没有命中任何 3D 对象
-        if (hits == null || hits.Count == 0)
+        //if (hits == null || hits.Count == 0)
-        {
+        //{
-            ViewportManager.ClearDicModels();
+        //    ViewportManager.ClearDicModels();
-            return;
+        //    return;
-        }
+        //}
-        var hit = hits[0];
+        //var hit = hits[0];
-        // 检查是否是 MeshGeometryModel3D
+        //// 检查是否是 MeshGeometryModel3D
-        if (hit.ModelHit is LineGeometryModel3D modelHit)
+        //if (hit.ModelHit is LineGeometryModel3D modelHit)
-        {
+        //{
-            // 获取几何信息
+        //    // 获取几何信息
-            if (modelHit != null)
+        //    if (modelHit != null)
-            {
+        //    {
-            }
+        //    }
-        }
+        //}
-        else
+        //else
-        {
+        //{
-            ViewportManager.ClearDicModels();
+        //    ViewportManager.ClearDicModels();
-        }
+        //}
     }
 }