feat(): 状态模式完成

Author: 聂彬

README.md

@@ -25,4 +25,5 @@
 16. 迭代器模式
 17. 中介者模式
 18. 备忘录模式
-19. 观察者模式
+19. 观察者模式
+20. 状态模式

lib/constant/string_const.dart

@@ -58,6 +58,10 @@ class StringConst {
 
   //备忘录模式
   static const String MEMORY_ = "备忘录模式";
+
   //备忘录模式
   static const String OBSERVER_ = "观察者模式";
+
+  //备忘录模式
+  static const String STATE_ = "状态模式";
 }

lib/main.dart

@@ -15,6 +15,7 @@ import 'package:flutter_design/page/memory/memory_page.dart';
 import 'package:flutter_design/page/midd/mid_page.dart';
 import 'package:flutter_design/page/observer/observer_page.dart';
 import 'package:flutter_design/page/proxy/proxy_page.dart';
+import 'package:flutter_design/page/state/state_page.dart';
 
 import 'constant/page_const.dart';
 import 'constant/string_const.dart';
@@ -53,6 +54,7 @@ class MyApp extends StatelessWidget {
         PageConst.MEDIATOR_PAGE: (context) => MidPage(),
         PageConst.MEMENTO_PAGE: (context) => MemoryPage(),
         PageConst.OBSERVER_PAGE: (context) => ObserverPage(),
+        PageConst.STATE_PAGE: (context) => StatePage(),
       },
     );
   }

lib/page/home_page.dart

@@ -34,6 +34,7 @@ Map<String, String> map = {
   PageConst.MEDIATOR_PAGE: StringConst.MID_,
   PageConst.MEMENTO_PAGE: StringConst.MEMORY_,
   PageConst.OBSERVER_PAGE: StringConst.OBSERVER_,
+  PageConst.STATE_PAGE: StringConst.STATE_,
 };
 
 class _HomePageState extends State<HomePage> {

lib/page/state/state_mode.dart

@@ -0,0 +1,75 @@
+import 'package:flutter/cupertino.dart';
+
+/// Created by NieBin on 2020-04-14
+/// Github: https://github.com/nb312
+/// Email: [email protected]
+///参考文章https://www.runoob.com/w3cnote/state-vs-strategy.html
+abstract class State {
+  void eatWater();
+
+  void watchSea();
+}
+
+class FlyState extends State {
+  @override
+  void eatWater() {
+    print("高空跳伞太危险不能喝水");
+  }
+
+  @override
+  void watchSea() {
+    print("飞得高看得远,整个大海都尽收眼底");
+  }
+}
+
+class SubWayState extends State {
+  @override
+  void eatWater() {
+    print("拿起你的矿泉水瓶开始喝水");
+  }
+
+  @override
+  void watchSea() {
+    print("拿起手机开始看大海的视频");
+  }
+}
+
+class HomeState extends State {
+  @override
+  void eatWater() {
+    print("用杯子倒一杯水喝了起来");
+  }
+
+  @override
+  void watchSea() {
+    print("打卡电视机,调到能看大海的频道");
+  }
+}
+
+//如果程序员要执行这些状态会怎么样呢
+class Programmer extends State {
+  FlyState _flyState = FlyState();
+  SubWayState _subWayState = SubWayState();
+  HomeState _homeState = HomeState();
+
+  State get fly => _flyState;
+
+  State get subway => _subWayState;
+
+  State get homeState => _homeState;
+  State state;
+
+  Programmer() {
+    state = homeState;
+  }
+
+  @override
+  void eatWater() {
+    state?.eatWater();
+  }
+
+  @override
+  void watchSea() {
+    state.watchSea();
+  }
+}

lib/page/state/state_page.dart

@@ -0,0 +1,71 @@
+import 'package:flutter/material.dart';
+import 'package:flutter_design/page/state/state_mode.dart' as s;
+
+/// Created by NieBin on 2020-04-14
+/// Github: https://github.com/nb312
+/// Email: [email protected]
+
+class StatePage extends StatefulWidget {
+  @override
+  _StatePageState createState() => _StatePageState();
+}
+
+class _StatePageState extends State<StatePage> {
+  s.Programmer _programmer;
+
+  @override
+  void initState() {
+    _programmer = s.Programmer();
+    super.initState();
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    return Scaffold(
+      appBar: AppBar(
+        title: Text("状态模式"),
+      ),
+      body: Container(
+        child: Column(
+          children: <Widget>[
+            FlatButton(
+              color: Colors.red,
+              child: Text("跳伞飞起来"),
+              onPressed: () {
+                _programmer.state = s.FlyState();
+              },
+            ),
+            FlatButton(
+              color: Colors.yellow,
+              child: Text("坐地铁"),
+              onPressed: () {
+                _programmer.state = s.SubWayState();
+              },
+            ),
+            FlatButton(
+              color: Colors.orange,
+              child: Text("在家里"),
+              onPressed: () {
+                _programmer.state = s.HomeState();
+              },
+            ),
+            FlatButton(
+              color: Colors.green,
+              child: Text("喝水"),
+              onPressed: () {
+                _programmer.eatWater();
+              },
+            ),
+            FlatButton(
+              color: Colors.pink,
+              child: Text("看海"),
+              onPressed: () {
+                _programmer.watchSea();
+              },
+            )
+          ],
+        ),
+      ),
+    );
+  }
+}