fix(): 修改装饰模式

Author: 聂彬

lib/page/decorator/decorator_mode.dart

@@ -3,48 +3,53 @@ import 'package:flutter/cupertino.dart';
 /// Created by NieBin on 2020-03-24
 /// Github: https://github.com/nb312
 /// Email: [email protected]
-abstract class Building {
-  final IPaint paint;
-
-  Building(this.paint);
+///
 
+abstract class Building {
   String decorate();
 }
 
-abstract class IPaint {
-  String decoration();
+class Paint implements Building {
+  final Building building;
+
+  Paint(this.building);
+
+  @override
+  String decorate() {
+    return "1.${building.decorate()}";
+  }
 }
 
 ///商业建筑
 class BusinessBuilding extends Building {
-  BusinessBuilding(IPaint paint) : super(paint);
-
   @override
   String decorate() {
-    return "装修商业楼\n${paint.decoration()}";
+    return "装修商业楼";
   }
 }
 
 ///居民楼
 class PersonBuilding extends Building {
-  PersonBuilding(IPaint paint) : super(paint);
-
   @override
   String decorate() {
-    return "装修居民楼\n${paint.decoration()}";
+    return "装修居民楼";
   }
 }
 
-class RedPaint extends IPaint {
+class RedPaint extends Paint {
+  RedPaint(Building building) : super(building);
+
   @override
-  String decoration() {
-    return "粉刷为红色";
+  String decorate() {
+    return "${super.decorate()}\n 2.粉刷为红色";
   }
 }
 
-class GreenPaint extends IPaint {
+class GreenPaint extends Paint {
+  GreenPaint(Building building) : super(building);
+
   @override
-  String decoration() {
-    return "粉刷为绿色";
+  String decorate() {
+    return "${super.decorate()}\n 2.粉刷为绿色";
   }
 }

lib/page/decorator/decorator_page.dart

@@ -48,9 +48,10 @@ class _DecoratorPageState extends State<DecoratorPage> {
                     onPressed: () {
                       setState(() {
                         isBusinessEven = !isBusinessEven;
-                        Building building = BusinessBuilding(
-                            isBusinessEven ? RedPaint() : GreenPaint());
-                        businessStr = building.decorate();
+                        Paint p = isBusinessEven
+                            ? RedPaint(BusinessBuilding())
+                            : GreenPaint(BusinessBuilding());
+                        businessStr = p.decorate();
                       });
                     },
                     child: Text(
@@ -81,9 +82,10 @@ class _DecoratorPageState extends State<DecoratorPage> {
                     onPressed: () {
                       setState(() {
                         isPersonEven = !isPersonEven;
-                        Building building = PersonBuilding(
-                            isPersonEven ? RedPaint() : GreenPaint());
-                        personStr = building.decorate();
+                        Paint p = isPersonEven
+                            ? RedPaint(PersonBuilding())
+                            : GreenPaint(PersonBuilding());
+                        personStr = p.decorate();
                       });
                     },
                     child: Text(