StatelessWidget

lib/guess/guess_page.dart

@@ -14,16 +14,30 @@ class GuessPage extends StatefulWidget {
   State<GuessPage> createState() => _GuessPageState();
 }
 
-class _GuessPageState extends State<GuessPage> {
+class _GuessPageState extends State<GuessPage> with SingleTickerProviderStateMixin{
+
+  late AnimationController controller;
+
+  @override
+  void initState() {
+    super.initState();
+    controller = AnimationController(
+      vsync: this,
+      duration: const Duration(milliseconds: 200),
+    );
+  }
+
   int _value = 0;
 
   Random _random = Random();
   bool _guessing = false;
   bool? _isBig;
 
+
   @override
   void dispose() {
     _guessCtrl.dispose();
+    controller.dispose();
     super.dispose();
   }
 
@@ -42,7 +56,7 @@ class _GuessPageState extends State<GuessPage> {
     int? guessValue = int.tryParse(_guessCtrl.text);
     // 游戏未开始，或者输入非整数，无视
     if (!_guessing || guessValue == null) return;
-
+    controller.forward(from: 0);
     //猜对了
     if (guessValue == _value) {
       setState(() {
@@ -70,10 +84,10 @@ class _GuessPageState extends State<GuessPage> {
           Column(
             children: [
               if(_isBig!)
-              ResultNotice(color:Colors.redAccent,info:'大了'),
+              ResultNotice(color:Colors.redAccent,info:'大了',controller: controller,),
               Spacer(),
               if(!_isBig!)
-              ResultNotice(color:Colors.blueAccent,info:'小了'),
+              ResultNotice(color:Colors.blueAccent,info:'小了',controller: controller,),
             ],
           ),
           Center(

lib/guess/result_notice.dart

@@ -1,54 +1,27 @@
 import 'package:flutter/material.dart';
 
-class ResultNotice extends StatefulWidget {
+class ResultNotice extends StatelessWidget {
   final Color color;
   final String info;
+  final AnimationController controller;
 
   const ResultNotice({
     Key? key,
     required this.color,
     required this.info,
+    required this.controller,
   }) : super(key: key);
 
-  @override
-  State<ResultNotice> createState() => _ResultNoticeState();
-}
-
-class _ResultNoticeState extends State<ResultNotice> with SingleTickerProviderStateMixin {
-  late AnimationController controller;
-
-  @override
-  void initState() {
-    super.initState();
-    controller = AnimationController(
-      vsync: this,
-      duration: const Duration(milliseconds: 200),
-    );
-    controller.forward();
-  }
-
-  @override
-  void dispose() {
-    controller.dispose();
-    super.dispose();
-  }
-
-  @override
-  void didUpdateWidget(covariant ResultNotice oldWidget) {
-    controller.forward(from: 0);
-    super.didUpdateWidget(oldWidget);
-  }
-
   @override
   Widget build(BuildContext context) {
     return Expanded(
       child: Container(
         alignment: Alignment.center,
-        color: widget.color,
+        color: color,
         child: AnimatedBuilder(
           animation: controller,
           builder: (_, child) => Text(
-            widget.info,
+            info,
             style: TextStyle(
               fontSize: 54 * (controller.value),
               color: Colors.white,