代码格式优化完毕

lib/widget_system/widgets/MultiChildRenderObjectWidget/Flex/node2_mainAxisAlignment.dart

@@ -12,41 +12,33 @@ import 'package:flutter/material.dart';
 //          "【mainAxisAlignment】 : 主轴对齐   【MainAxisAlignment】",
 //    }
 class MainAxisAlignmentFlex extends StatelessWidget {
+  MainAxisAlignmentFlex({Key? key}) : super(key: key);
 
   static TextStyle textStyle =
-  TextStyle(color: Colors.white, fontWeight: FontWeight.bold);
+      const TextStyle(color: Colors.white, fontWeight: FontWeight.bold);
 
-  final blueBox = Container(
+  final Widget blueBox = Container(
     alignment: Alignment.center,
     color: Colors.blue,
     height: 20,
     width: 30,
-    child: Text(
-      '1',
-      style: textStyle,
-    ),
+    child: Text('1', style: textStyle),
   );
 
-  final redBox = Container(
+  final Widget redBox = Container(
     alignment: Alignment.center,
     color: Colors.red,
     height: 30,
     width: 40,
-    child: Text(
-      '2',
-      style: textStyle,
-    ),
+    child: Text('2', style: textStyle),
   );
 
-  final greenBox = Container(
+  final Widget greenBox = Container(
     alignment: Alignment.center,
     color: Colors.green,
     height: 20,
     width: 20,
-    child: Text(
-      '3',
-      style: textStyle,
-    ),
+    child: Text('3', style: textStyle),
   );
 
   @override
@@ -56,7 +48,7 @@ class MainAxisAlignmentFlex extends StatelessWidget {
         children: MainAxisAlignment.values
             .map((mode) => Column(children: <Widget>[
           Container(
-              margin: EdgeInsets.all(5),
+              margin: const EdgeInsets.all(5),
               width: 160,
               height: 80,
               color: Colors.grey.withAlpha(33),
@@ -66,7 +58,7 @@ class MainAxisAlignmentFlex extends StatelessWidget {
             .toList());
   }
 
-  _buildItem(mode) => Flex(
+  Widget _buildItem(mode) => Flex(
     direction: Axis.horizontal,
     mainAxisAlignment: mode,
     children: <Widget>[