案例优化

lib/widget_system/widgets/SingleChildRenderObjectWidget/SizedOverflowBox/node1_base.dart

@@ -13,6 +13,7 @@ import 'package:flutter/material.dart';
 //          "【alignment】 : 对齐方式   【AlignmentGeometry】",
 //    }
 class CustomSizedOverflowBox extends StatefulWidget {
+  const CustomSizedOverflowBox({Key? key}) : super(key: key);
 
   @override
   _CustomSizedOverflowBoxState createState() => _CustomSizedOverflowBoxState();
@@ -24,7 +25,7 @@ class _CustomSizedOverflowBoxState extends State<CustomSizedOverflowBox> {
 
   @override
   Widget build(BuildContext context) {
-    var box = SizedOverflowBox(
+    Widget box = SizedOverflowBox(
       alignment: Alignment.bottomRight,
       size: Size(_x, _y),
       child: Container(width: 30, height: 50, color: Colors.orange),