fix：关于焦点获取问题

Views/UserControl/ViewportData/Helper/ViewportHelperPro.cs

@@ -1417,9 +1417,24 @@ public class ViewportHelperPro
                 lineDirection.Normalize();
                 // 现在鼠标对于3d模型的位置
                 var mousePosition = ev.Position;
-                var currentMousePosition = Get3DPointFromMouse(mousePosition);
+                Point3D currentMousePosition = new();
+                try { 
+                    currentMousePosition = Get3DPointFromMouse(mousePosition);
+                }
+                catch
+                {
+                    return;
+                }
                 currentMousePosition.Y = Y;
-                var hitPoint = Get3DPointFromMouse(startDragPoint); 
+                Point3D hitPoint = new();
+                try
+                {
+                    hitPoint = Get3DPointFromMouse(startDragPoint);
+                }
+                catch
+                {
+                    return;
+                }
                 hitPoint.Y = Y;
                 // 计算鼠标移动的方向
                 var moveDirection = currentMousePosition - hitPoint;
@@ -1673,8 +1688,14 @@ public class ViewportHelperPro
                 var Y = line.Geometry.Positions[0].Y;
                 var center = ViewportManager.CenterVector;
                 center.Y = Y;
-
-                Point3D mouseWorldPosition = Get3DPointFromMouse(mousePosition);
+                Point3D mouseWorldPosition = new();
+                try { 
+                    mouseWorldPosition = Get3DPointFromMouse(mousePosition);
+                }
+                catch
+                {
+                    return;
+                }
                 mouseWorldPosition.Y = Y;
                 // Console.WriteLine($"鼠标在3D模型中的位置：{mouseWorldPosition.X},{mouseWorldPosition.Y},{mouseWorldPosition.Z}");
                 // 计算鼠标与圆心的距离