修正测试错误

__test__/Geometry/EdgeGeometry.test.ts

@@ -12,7 +12,7 @@ test('EdgeGeometry生成', () =>
 
     let obj = br.GetDrawObjectFromRenderType(RenderType.Wireframe);
 
-    let line = obj.children[0] as Line;
+    let line = obj as Line;
 
     let geo = line.geometry;
 

src/DatabaseServices/Entity.ts

@@ -251,7 +251,8 @@ export class Entity extends CADObject
 
     UpdateVisible()
     {
-        this._drawObject.visible = !this._isErase && this._Visible;
+        if (this._drawObject)
+            this._drawObject.visible = !this._isErase && this._Visible;
     }
 
     //#endregion