refactor: 抽出语音作答与录音回听的公共逻辑

对话页、AI 补练页、课程跟读步骤、独立表达步骤和评估页各自复制了一套
"录音 → AI 转写 → 填入答案"的流程，其中 3 页还复制了"录音回听/播放/删除"
的按钮和方法。现在统一到 lib/widgets/voice_answer.dart：
- VoiceAnswerMixin：startVoiceInput / finishVoiceInput / toggleRecording /
  playRecording / deleteRecording / disposeVoiceAnswer，状态字段名沿用各页原名，
  页面的 build 代码基本不动；
- RecordingControls：录音回听按钮行。

用户可见的变化：
- "未识别到语音"提示统一为「未识别到清晰语音，请再试一次或直接输入文字。」
  （对话页、补练页、独立表达步骤、评估页原本各有不同说法；跟读步骤保留
  原来提示"播放示范音"的文案）。麦克风不可用、开始录音的提示保持各页原样。
- 对话页的录音回听按钮与播放按钮之间增加 8px 间距，与其他页面一致。
- 删除录音时先停止正在播放的录音（原来只有跟读步骤这样做）。
- 离开页面时，如果还在录音或设备识别中，会先停止；不保留录音时一并删除
  这段录音文件。原来课程两个步骤离开时不停止录音，各页离开时也不停止
  "录音回听"的录音。

flutter analyze 无问题，flutter test 142 个测试通过；现有测试未覆盖麦克风流程。

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

kouyu_english/lib/features/assessment/assessment_page.dart

@@ -1,4 +1,3 @@
-import '../../core/ai_service.dart';
 import 'package:flutter/material.dart';
 
 import '../../core/app_state.dart';
@@ -7,6 +6,7 @@ import '../../core/assessment_bank.dart';
 import '../../core/models.dart';
 import '../../core/voice_service.dart';
 import '../../widgets/app_widgets.dart';
+import '../../widgets/voice_answer.dart';
 
 class AssessmentPreparationPage extends StatefulWidget {
   const AssessmentPreparationPage({
@@ -129,16 +129,14 @@ class AssessmentPage extends StatefulWidget {
   State<AssessmentPage> createState() => _AssessmentPageState();
 }
 
-class _AssessmentPageState extends State<AssessmentPage> {
+class _AssessmentPageState extends State<AssessmentPage>
+    with VoiceAnswerMixin<AssessmentPage> {
   final controller = TextEditingController();
   final Map<String, bool> results = {};
   int index = 0;
   bool usedMic = false;
   bool transcriptEdited = false;
   String lastTranscript = '';
-  bool listening = false;
-  bool transcribing = false;
-  bool aiVoiceRecording = false;
   bool audioPlayed = false;
   bool speakingUnavailable = false;
   AssessmentRecord? completedRecord;
@@ -160,10 +158,7 @@ class _AssessmentPageState extends State<AssessmentPage> {
   void dispose() {
     VoiceService.instance.stopSpeaking();
     VoiceService.instance.stopListening();
-    VoiceService.instance.stopRecordingPlayback();
+    disposeVoiceAnswer(keepRecording: true);
-    if (listening || aiVoiceRecording) {
-      VoiceService.instance.stopRecording();
-    }
     controller.dispose();
     super.dispose();
   }
@@ -175,62 +170,31 @@ class _AssessmentPageState extends State<AssessmentPage> {
     if (mounted) setState(() => audioPlayed = true);
   }
 
+  @override
+  AppState get voiceState => widget.state;
+
   Future<void> _mic() async {
     if (aiVoiceRecording) {
-      final path = await VoiceService.instance.stopRecording();
+      await finishVoiceInput(
-      if (!mounted) return;
+        keepAudio: false,
-      setState(() {
+        onTranscript: (text) {
-        aiVoiceRecording = false;
+          controller.text = text;
-        listening = false;
+          usedMic = true;
-        transcribing = true;
+          lastTranscript = text;
-      });
+          transcriptEdited = false;
-      if (path != null) {
+          speakingUnavailable = false;
-        final config = widget.state.aiConfig;
+        },
-        final transcribed = await AiService.instance.transcribeAudio(
+      );
-          filePath: path,
-          provider: config.provider,
-          endpoint: config.endpoint,
-          model: config.model,
-        );
-        if (mounted) {
-          setState(() {
-            transcribing = false;
-            if (transcribed != null && transcribed.trim().isNotEmpty) {
-              controller.text = transcribed.trim();
-              usedMic = true;
-              lastTranscript = transcribed.trim();
-              transcriptEdited = false;
-              speakingUnavailable = false;
-            }
-          });
-          if (transcribed == null || transcribed.trim().isEmpty) {
-            ScaffoldMessenger.of(context).showSnackBar(
-              const SnackBar(content: Text('未识别到清晰语音，请再试一次。')),
-            );
-          }
-        }
-      } else {
-        if (mounted) setState(() => transcribing = false);
-      }
       return;
     }
 
-    VoiceService.instance.stopSpeaking();
+    final recordStarted = await startVoiceInput(
-    final recordStarted = await VoiceService.instance.startRecording();
+      unavailableMessage: '无法访问麦克风，口语可稍后补测。',
+    );
     if (!mounted) return;
-    setState(() {
+    setState(() => speakingUnavailable = !recordStarted);
-      aiVoiceRecording = recordStarted;
-      listening = recordStarted;
-      speakingUnavailable = !recordStarted;
-    });
     if (recordStarted) {
-      ScaffoldMessenger.of(context).showSnackBar(
+      showVoiceMessage('已启动麦克风录音，回答后再次点击，将自动转写为英文。');
-        const SnackBar(content: Text('已启动麦克风录音，回答后再次点击，将自动转写为英文。')),
-      );
-    } else {
-      ScaffoldMessenger.of(context).showSnackBar(
-        const SnackBar(content: Text('无法访问麦克风，口语可稍后补测。')),
-      );
     }
   }
 

kouyu_english/lib/features/dialogue/dialogue_flow.dart

@@ -8,6 +8,7 @@ import '../../core/seed_courses.dart';
 import '../../core/voice_service.dart';
 import '../../widgets/app_widgets.dart';
 import '../../widgets/lexicon_lookup.dart';
+import '../../widgets/voice_answer.dart';
 
 class DialogueScenePage extends StatelessWidget {
   const DialogueScenePage({
@@ -105,22 +106,17 @@ class DialoguePage extends StatefulWidget {
   State<DialoguePage> createState() => _DialoguePageState();
 }
 
-class _DialoguePageState extends State<DialoguePage> {
+class _DialoguePageState extends State<DialoguePage>
+    with VoiceAnswerMixin<DialoguePage> {
   final controller = TextEditingController();
   final ScrollController _scrollController = ScrollController();
   final List<DialogueTurn> turns = [];
   int stage = 0;
   bool usedHelp = false;
   String? hint;
-  bool listening = false;
-  bool recording = false;
-  bool transcribing = false;
-  bool aiVoiceRecording = false;
-  bool playingRecording = false;
   bool usedVoice = false;
   bool transcriptEdited = false;
   String lastTranscript = '';
-  String? recordingPath;
   bool waitingForReply = false;
   String? validationError;
 
@@ -260,13 +256,7 @@ class _DialoguePageState extends State<DialoguePage> {
   void dispose() {
     VoiceService.instance.stopSpeaking();
     VoiceService.instance.stopListening();
-    VoiceService.instance.stopRecordingPlayback();
+    disposeVoiceAnswer(keepRecording: widget.state.keepRecordings);
-    if (listening || aiVoiceRecording) {
-      VoiceService.instance.stopRecording();
-    }
-    if (!widget.state.keepRecordings) {
-      VoiceService.instance.deleteRecording(recordingPath);
-    }
     _scrollController.dispose();
     controller.dispose();
     super.dispose();
@@ -542,102 +532,23 @@ class _DialoguePageState extends State<DialoguePage> {
     _saveDraft();
   }
 
+  @override
+  AppState get voiceState => widget.state;
+
   Future<void> _toggleListening() async {
-    if (listening || aiVoiceRecording) {
+    if (aiVoiceRecording) {
-      final path = await VoiceService.instance.stopRecording();
+      await finishVoiceInput(
-      if (!mounted) return;
+        onTranscript: (text) {
-      setState(() {
+          controller.text = text;
-        aiVoiceRecording = false;
+          usedVoice = true;
-        listening = false;
+          lastTranscript = text;
-        transcribing = true;
+          transcriptEdited = false;
-        recordingPath = path;
+        },
-      });
+        afterTranscribe: _scrollToBottom,
-      if (path != null) {
-        final config = widget.state.aiConfig;
-        final transcribed = await AiService.instance.transcribeAudio(
-          filePath: path,
-          provider: config.provider,
-          endpoint: config.endpoint,
-          model: config.model,
-        );
-        if (mounted) {
-          setState(() {
-            transcribing = false;
-            if (transcribed != null && transcribed.trim().isNotEmpty) {
-              controller.text = transcribed.trim();
-              usedVoice = true;
-              lastTranscript = transcribed.trim();
-              transcriptEdited = false;
-            }
-          });
-          _scrollToBottom();
-          if (transcribed == null || transcribed.trim().isEmpty) {
-            ScaffoldMessenger.of(context).showSnackBar(
-              const SnackBar(content: Text('未识别到清晰语音，请再试一次或使用键盘输入。')),
-            );
-          }
-        }
-      } else {
-        if (mounted) setState(() => transcribing = false);
-      }
-      return;
-    }
-
-    VoiceService.instance.stopSpeaking();
-    final recordStarted = await VoiceService.instance.startRecording();
-    if (!mounted) return;
-    if (recordStarted) {
-      setState(() {
-        aiVoiceRecording = true;
-        listening = true;
-      });
-    } else {
-      ScaffoldMessenger.of(context).showSnackBar(
-        const SnackBar(content: Text('无法访问麦克风，请检查手机录音权限。')),
       );
-    }
-  }
-
-  Future<void> _toggleRecording() async {
-    if (recording) {
-      final path = await VoiceService.instance.stopRecording();
-      if (mounted) {
-        setState(() {
-          recording = false;
-          recordingPath = path;
-        });
-      }
       return;
     }
-    await VoiceService.instance.deleteRecording(recordingPath);
+    await startVoiceInput();
-    final ready = await VoiceService.instance.startRecording();
-    if (!mounted) return;
-    setState(() {
-      recording = ready;
-      if (ready) recordingPath = null;
-    });
-    if (!ready) {
-      ScaffoldMessenger.of(
-        context,
-      ).showSnackBar(const SnackBar(content: Text('无法使用麦克风录音；请检查系统权限。')));
-    }
-  }
-
-  Future<void> _playRecording() async {
-    final path = recordingPath;
-    if (path == null) return;
-    setState(() => playingRecording = true);
-    await VoiceService.instance.playRecording(
-      path,
-      onComplete: () {
-        if (mounted) setState(() => playingRecording = false);
-      },
-    );
-  }
-
-  Future<void> _deleteRecording() async {
-    await VoiceService.instance.deleteRecording(recordingPath);
-    if (mounted) setState(() => recordingPath = null);
   }
 
   void _showWord() => showLexiconLookup(
@@ -919,32 +830,13 @@ class _DialoguePageState extends State<DialoguePage> {
                     : '这是设备转写；未修改提交后会作为语音尝试保存。',
                 style: const TextStyle(color: AppColors.muted, fontSize: 12),
               ),
-            Row(
+            RecordingControls(
-              children: [
+              recording: recording,
-                Expanded(
+              playing: playingRecording,
-                  child: OutlinedButton.icon(
+              hasRecording: recordingPath != null,
-                    onPressed: _toggleRecording,
+              onToggleRecording: toggleRecording,
-                    icon: Icon(
+              onPlay: playRecording,
-                      recording
+              onDelete: deleteRecording,
-                          ? Icons.stop_circle_outlined
-                          : Icons.fiber_manual_record,
-                    ),
-                    label: Text(recording ? '停止录音' : '录音回听'),
-                  ),
-                ),
-                if (recordingPath != null) ...[
-                  IconButton(
-                    tooltip: playingRecording ? '正在播放' : '回听录音',
-                    onPressed: playingRecording ? null : _playRecording,
-                    icon: const Icon(Icons.play_arrow),
-                  ),
-                  IconButton(
-                    tooltip: '删除录音',
-                    onPressed: _deleteRecording,
-                    icon: const Icon(Icons.delete_outline),
-                  ),
-                ],
-              ],
             ),
             Text(
               widget.state.keepRecordings

kouyu_english/lib/features/lesson/lesson_flow.dart

@@ -9,6 +9,7 @@ import '../../core/voice_service.dart';
 import '../../core/writing_feedback.dart';
 import '../../widgets/app_widgets.dart';
 import '../../widgets/lexicon_lookup.dart';
+import '../../widgets/voice_answer.dart';
 
 class LessonFlow extends StatefulWidget {
   const LessonFlow({
@@ -448,55 +449,25 @@ class _SpeakingStep extends StatefulWidget {
   State<_SpeakingStep> createState() => _SpeakingStepState();
 }
 
-class _SpeakingStepState extends State<_SpeakingStep> {
+class _SpeakingStepState extends State<_SpeakingStep>
-  bool listening = false;
+    with VoiceAnswerMixin<_SpeakingStep> {
-  bool transcribing = false;
-  bool playingRecording = false;
   String transcript = '';
-  String? recordingPath;
+
+  @override
+  AppState get voiceState => widget.state;
 
   @override
   void dispose() {
-    VoiceService.instance.stopRecordingPlayback();
+    disposeVoiceAnswer(keepRecording: widget.keepRecording);
-    if (!widget.keepRecording) {
-      VoiceService.instance.deleteRecording(recordingPath);
-    }
     super.dispose();
   }
 
   Future<void> _toggleMic() async {
-    if (listening) {
+    if (aiVoiceRecording) {
-      final path = await VoiceService.instance.stopRecording();
+      await finishVoiceInput(
-      if (!mounted) return;
+        noSpeech: '未识别到清晰发音，请重试或点击“播放示范音”。',
-      setState(() {
+        onTranscript: (text) => transcript = text,
-        listening = false;
+      );
-        transcribing = true;
-        recordingPath = path;
-      });
-      if (path != null) {
-        final config = widget.state.aiConfig;
-        final text = await AiService.instance.transcribeAudio(
-          filePath: path,
-          provider: config.provider,
-          endpoint: config.endpoint,
-          model: config.model,
-        );
-        if (mounted) {
-          setState(() {
-            transcribing = false;
-            if (text != null && text.trim().isNotEmpty) {
-              transcript = text.trim();
-            }
-          });
-          if (text == null || text.trim().isEmpty) {
-            ScaffoldMessenger.of(context).showSnackBar(
-              const SnackBar(content: Text('未识别到清晰发音，请重试或点击“播放示范音”。')),
-            );
-          }
-        }
-      } else {
-        if (mounted) setState(() => transcribing = false);
-      }
       return;
     }
 
@@ -506,24 +477,10 @@ class _SpeakingStepState extends State<_SpeakingStep> {
       await VoiceService.instance.deleteRecording(recordingPath);
     }
 
-    final recordStarted = await VoiceService.instance.startRecording();
+    final recordStarted = await startVoiceInput();
-    if (mounted) {
+    if (!recordStarted || !mounted) return;
-      setState(() {
+    setState(() => recordingPath = null);
-        listening = recordStarted;
+    showVoiceMessage('已启动麦克风录音，跟读完成后再次点击，AI 将自动转写发音。');
-        if (recordStarted) {
-          recordingPath = null;
-        }
-      });
-      if (recordStarted) {
-        ScaffoldMessenger.of(context).showSnackBar(
-          const SnackBar(content: Text('已启动麦克风录音，跟读完成后再次点击，AI 将自动转写发音。')),
-        );
-      } else {
-        ScaffoldMessenger.of(context).showSnackBar(
-          const SnackBar(content: Text('无法访问麦克风，请检查手机录音权限。')),
-        );
-      }
-    }
   }
 
   Future<void> _togglePlayRecording() async {
@@ -538,24 +495,7 @@ class _SpeakingStepState extends State<_SpeakingStep> {
       );
       return;
     }
-    setState(() => playingRecording = true);
+    await playRecording();
-    await VoiceService.instance.playRecording(
-      recordingPath!,
-      onComplete: () {
-        if (mounted) setState(() => playingRecording = false);
-      },
-    );
-  }
-
-  Future<void> _deleteRecording() async {
-    await VoiceService.instance.stopRecordingPlayback();
-    await VoiceService.instance.deleteRecording(recordingPath);
-    if (mounted) {
-      setState(() {
-        recordingPath = null;
-        playingRecording = false;
-      });
-    }
   }
 
   @override
@@ -615,7 +555,7 @@ class _SpeakingStepState extends State<_SpeakingStep> {
                     const SizedBox(width: 8),
                     IconButton(
                       tooltip: '删除录音',
-                      onPressed: (listening || transcribing) ? null : _deleteRecording,
+                      onPressed: (listening || transcribing) ? null : deleteRecording,
                       icon: const Icon(Icons.delete_outline),
                     ),
                   ],
@@ -1188,24 +1128,19 @@ class _IndependentStep extends StatefulWidget {
   State<_IndependentStep> createState() => _IndependentStepState();
 }
 
-class _IndependentStepState extends State<_IndependentStep> {
+class _IndependentStepState extends State<_IndependentStep>
-  bool listening = false;
+    with VoiceAnswerMixin<_IndependentStep> {
-  bool recording = false;
-  bool transcribing = false;
-  bool aiVoiceRecording = false;
-  bool playingRecording = false;
   bool usedVoice = false;
   bool transcriptEdited = false;
   String lastTranscript = '';
-  String? recordingPath;
   String? validationError;
 
+  @override
+  AppState get voiceState => widget.state;
+
   @override
   void dispose() {
-    VoiceService.instance.stopRecordingPlayback();
+    disposeVoiceAnswer(keepRecording: widget.keepRecording);
-    if (!widget.keepRecording) {
-      VoiceService.instance.deleteRecording(recordingPath);
-    }
     super.dispose();
   }
 
@@ -1220,86 +1155,17 @@ class _IndependentStepState extends State<_IndependentStep> {
     );
   }
 
-  Future<void> _toggleRecording() async {
-    if (recording) {
-      final path = await VoiceService.instance.stopRecording();
-      if (mounted) {
-        setState(() {
-          recording = false;
-          recordingPath = path;
-        });
-      }
-      return;
-    }
-    await VoiceService.instance.deleteRecording(recordingPath);
-    final ready = await VoiceService.instance.startRecording();
-    if (!mounted) return;
-    setState(() {
-      recording = ready;
-      if (ready) recordingPath = null;
-    });
-    if (!ready) {
-      ScaffoldMessenger.of(
-        context,
-      ).showSnackBar(const SnackBar(content: Text('无法使用麦克风录音；请检查系统权限。')));
-    }
-  }
-
-  Future<void> _playRecording() async {
-    final path = recordingPath;
-    if (path == null) return;
-    setState(() => playingRecording = true);
-    await VoiceService.instance.playRecording(
-      path,
-      onComplete: () {
-        if (mounted) setState(() => playingRecording = false);
-      },
-    );
-  }
-
-  Future<void> _deleteRecording() async {
-    await VoiceService.instance.deleteRecording(recordingPath);
-    if (mounted) setState(() => recordingPath = null);
-  }
-
   Future<void> _toggleMic() async {
     if (aiVoiceRecording) {
-      final path = await VoiceService.instance.stopRecording();
+      await finishVoiceInput(
-      if (!mounted) return;
+        onTranscript: (text) {
-      setState(() {
+          widget.controller.text = text;
-        aiVoiceRecording = false;
+          usedVoice = true;
-        listening = false;
+          lastTranscript = text;
-        transcribing = true;
+          transcriptEdited = false;
-        recordingPath = path;
+        },
-      });
+        afterTranscribe: widget.onChanged,
-      if (path != null) {
+      );
-        final config = widget.state.aiConfig;
-        final text = await AiService.instance.transcribeAudio(
-          filePath: path,
-          provider: config.provider,
-          endpoint: config.endpoint,
-          model: config.model,
-        );
-        if (mounted) {
-          setState(() {
-            transcribing = false;
-            if (text != null && text.trim().isNotEmpty) {
-              widget.controller.text = text.trim();
-              usedVoice = true;
-              lastTranscript = text.trim();
-              transcriptEdited = false;
-            }
-          });
-          widget.onChanged();
-          if (text == null || text.trim().isEmpty) {
-            ScaffoldMessenger.of(context).showSnackBar(
-              const SnackBar(content: Text('未识别到声音，请重试或直接打字输入。')),
-            );
-          }
-        }
-      } else {
-        if (mounted) setState(() => transcribing = false);
-      }
       return;
     }
 
@@ -1333,21 +1199,9 @@ class _IndependentStepState extends State<_IndependentStep> {
     );
 
     if (!ready) {
-      final recordStarted = await VoiceService.instance.startRecording();
+      final recordStarted = await startVoiceInput();
-      if (mounted) {
+      if (recordStarted && mounted) {
-        setState(() {
+        showVoiceMessage('已启动麦克风录音，说完后再次点击，AI 将自动转写为英文。');
-          aiVoiceRecording = recordStarted;
-          listening = recordStarted;
-        });
-        if (recordStarted) {
-          ScaffoldMessenger.of(context).showSnackBar(
-            const SnackBar(content: Text('已启动麦克风录音，说完后再次点击，AI 将自动转写为英文。')),
-          );
-        } else {
-          ScaffoldMessenger.of(context).showSnackBar(
-            const SnackBar(content: Text('无法访问麦克风，请检查手机录音权限。')),
-          );
-        }
       }
       return;
     }
@@ -1404,33 +1258,13 @@ class _IndependentStepState extends State<_IndependentStep> {
                     ? '可录下这次尝试并保存在本机；不会发送给 AI。'
                     : '可录下这次尝试并回听；离开本页后会自动删除。',
               ),
-              Row(
+              RecordingControls(
-                children: [
+                recording: recording,
-                  Expanded(
+                playing: playingRecording,
-                    child: OutlinedButton.icon(
+                hasRecording: recordingPath != null,
-                      onPressed: _toggleRecording,
+                onToggleRecording: toggleRecording,
-                      icon: Icon(
+                onPlay: playRecording,
-                        recording
+                onDelete: deleteRecording,
-                            ? Icons.stop_circle_outlined
-                            : Icons.fiber_manual_record,
-                      ),
-                      label: Text(recording ? '停止录音' : '录音回听'),
-                    ),
-                  ),
-                  if (recordingPath != null) ...[
-                    const SizedBox(width: 8),
-                    IconButton(
-                      tooltip: playingRecording ? '正在播放' : '回听录音',
-                      onPressed: playingRecording ? null : _playRecording,
-                      icon: const Icon(Icons.play_arrow),
-                    ),
-                    IconButton(
-                      tooltip: '删除录音',
-                      onPressed: _deleteRecording,
-                      icon: const Icon(Icons.delete_outline),
-                    ),
-                  ],
-                ],
               ),
             ],
           ),

kouyu_english/lib/features/review/review_page.dart

@@ -10,6 +10,7 @@ import '../../core/review_feedback.dart';
 import '../../core/a0_core.dart';
 import '../../core/voice_service.dart';
 import '../../widgets/app_widgets.dart';
+import '../../widgets/voice_answer.dart';
 
 class ReviewPage extends StatefulWidget {
   const ReviewPage({
@@ -313,21 +314,16 @@ class AdaptiveLessonPage extends StatefulWidget {
   State<AdaptiveLessonPage> createState() => _AdaptiveLessonPageState();
 }
 
-class _AdaptiveLessonPageState extends State<AdaptiveLessonPage> {
+class _AdaptiveLessonPageState extends State<AdaptiveLessonPage>
+    with VoiceAnswerMixin<AdaptiveLessonPage> {
   final controller = TextEditingController();
   int index = 0;
   bool showReference = false;
   String? answerFeedback;
-  bool listening = false;
-  bool transcribing = false;
-  bool aiVoiceRecording = false;
   bool usedVoice = false;
   bool transcriptEdited = false;
   bool transcriptConfirmed = false;
   String lastTranscript = '';
-  bool recording = false;
-  bool playingRecording = false;
-  String? recordingPath;
 
   @override
   void initState() {
@@ -353,13 +349,7 @@ class _AdaptiveLessonPageState extends State<AdaptiveLessonPage> {
   void dispose() {
     VoiceService.instance.stopSpeaking();
     VoiceService.instance.stopListening();
-    VoiceService.instance.stopRecordingPlayback();
+    disposeVoiceAnswer(keepRecording: widget.state.keepRecordings);
-    if (listening || aiVoiceRecording) {
-      VoiceService.instance.stopRecording();
-    }
-    if (!widget.state.keepRecordings) {
-      VoiceService.instance.deleteRecording(recordingPath);
-    }
     controller.dispose();
     super.dispose();
   }
@@ -428,105 +418,32 @@ class _AdaptiveLessonPageState extends State<AdaptiveLessonPage> {
     });
   }
 
+  @override
+  AppState get voiceState => widget.state;
+
   Future<void> _toggleListening() async {
-    if (listening || aiVoiceRecording) {
+    if (aiVoiceRecording) {
-      final path = await VoiceService.instance.stopRecording();
+      await finishVoiceInput(
-      if (!mounted) return;
+        keepAudio: false,
-      setState(() {
+        onTranscript: (text) {
-        aiVoiceRecording = false;
+          controller.text = text;
-        listening = false;
+          usedVoice = true;
-        transcribing = true;
+          transcriptEdited = false;
-      });
+          transcriptConfirmed = false;
-      if (path != null) {
+          lastTranscript = text;
-        final config = widget.state.aiConfig;
+        },
-        final transcribed = await AiService.instance.transcribeAudio(
+        afterTranscribe: () {
-          filePath: path,
-          provider: config.provider,
-          endpoint: config.endpoint,
-          model: config.model,
-        );
-        if (mounted) {
-          setState(() {
-            transcribing = false;
-            if (transcribed != null && transcribed.trim().isNotEmpty) {
-              controller.text = transcribed.trim();
-              usedVoice = true;
-              transcriptEdited = false;
-              transcriptConfirmed = false;
-              lastTranscript = transcribed.trim();
-            }
-          });
           final lesson = widget.state.cachedAdaptiveLesson;
           if (lesson != null) _saveDraft(lesson);
-          if (transcribed == null || transcribed.trim().isEmpty) {
+        },
-            ScaffoldMessenger.of(context).showSnackBar(
-              const SnackBar(content: Text('未识别到清晰语音，请再试一次或输入文本。')),
-            );
-          }
-        }
-      } else {
-        if (mounted) setState(() => transcribing = false);
-      }
-      return;
-    }
-
-    VoiceService.instance.stopSpeaking();
-    final recordStarted = await VoiceService.instance.startRecording();
-    if (!mounted) return;
-    if (recordStarted) {
-      setState(() {
-        aiVoiceRecording = true;
-        listening = true;
-      });
-    } else {
-      ScaffoldMessenger.of(context).showSnackBar(
-        const SnackBar(content: Text('无法访问麦克风，请检查录音权限。你仍可输入英文完成补练。')),
       );
-    }
-  }
-
-  Future<void> _toggleRecording() async {
-    if (recording) {
-      final path = await VoiceService.instance.stopRecording();
-      if (mounted) {
-        setState(() {
-          recording = false;
-          recordingPath = path;
-        });
-      }
       return;
     }
-    await VoiceService.instance.deleteRecording(recordingPath);
+    await startVoiceInput(
-    final ready = await VoiceService.instance.startRecording();
+      unavailableMessage: '无法访问麦克风，请检查录音权限。你仍可输入英文完成补练。',
-    if (!mounted) return;
-    setState(() {
-      recording = ready;
-      if (ready) recordingPath = null;
-    });
-    if (!ready) {
-      ScaffoldMessenger.of(
-        context,
-      ).showSnackBar(const SnackBar(content: Text('无法使用麦克风录音；请检查系统权限。')));
-    }
-  }
-
-  Future<void> _playRecording() async {
-    final path = recordingPath;
-    if (path == null) return;
-    setState(() => playingRecording = true);
-    await VoiceService.instance.playRecording(
-      path,
-      onComplete: () {
-        if (mounted) setState(() => playingRecording = false);
-      },
     );
   }
 
-  Future<void> _deleteRecording() async {
-    await VoiceService.instance.deleteRecording(recordingPath);
-    if (mounted) setState(() => recordingPath = null);
-  }
-
   @override
   Widget build(BuildContext context) {
     final lesson = widget.state.cachedAdaptiveLesson;
@@ -682,33 +599,13 @@ class _AdaptiveLessonPageState extends State<AdaptiveLessonPage> {
                         ? '可录音回听并仅保存在本机；不会发送给 AI。'
                         : '可录音回听；离开本页后会自动删除。',
                   ),
-                  Row(
+                  RecordingControls(
-                    children: [
+                    recording: recording,
-                      Expanded(
+                    playing: playingRecording,
-                        child: OutlinedButton.icon(
+                    hasRecording: recordingPath != null,
-                          onPressed: listening ? null : _toggleRecording,
+                    onToggleRecording: listening ? null : toggleRecording,
-                          icon: Icon(
+                    onPlay: playRecording,
-                            recording
+                    onDelete: deleteRecording,
-                                ? Icons.stop_circle_outlined
-                                : Icons.fiber_manual_record,
-                          ),
-                          label: Text(recording ? '停止录音' : '录音回听'),
-                        ),
-                      ),
-                      if (recordingPath != null) ...[
-                        const SizedBox(width: 8),
-                        IconButton(
-                          tooltip: playingRecording ? '正在播放' : '回听录音',
-                          onPressed: playingRecording ? null : _playRecording,
-                          icon: const Icon(Icons.play_arrow),
-                        ),
-                        IconButton(
-                          tooltip: '删除录音',
-                          onPressed: _deleteRecording,
-                          icon: const Icon(Icons.delete_outline),
-                        ),
-                      ],
-                    ],
                   ),
                 ],
               ),

kouyu_english/lib/widgets/voice_answer.dart

@@ -0,0 +1,205 @@
+import 'package:flutter/material.dart';
+
+import '../core/ai_service.dart';
+import '../core/app_state.dart';
+import '../core/voice_service.dart';
+
+/// Microphone handling shared by pages where the learner speaks an answer.
+///
+/// Two independent flows use the microphone:
+/// * voice input records an answer and transcribes it into text
+///   ([aiVoiceRecording], [listening], [transcribing]);
+/// * the playback recorder keeps an attempt to listen back to
+///   ([recording], [playingRecording], [recordingPath]).
+mixin VoiceAnswerMixin<T extends StatefulWidget> on State<T> {
+  static const noSpeechMessage = '未识别到清晰语音，请再试一次或直接输入文字。';
+  static const micUnavailableMessage = '无法访问麦克风，请检查手机录音权限。';
+
+  /// Supplies the AI configuration used for transcription.
+  AppState get voiceState;
+
+  /// The microphone is recording an answer to transcribe. A page that also
+  /// uses device speech recognition sets [listening] alone for that.
+  bool aiVoiceRecording = false;
+  bool listening = false;
+  bool transcribing = false;
+  bool recording = false;
+  bool playingRecording = false;
+  String? recordingPath;
+
+  void showVoiceMessage(String message) {
+    ScaffoldMessenger.of(
+      context,
+    ).showSnackBar(SnackBar(content: Text(message)));
+  }
+
+  /// Starts recording an answer for transcription and reports whether the
+  /// microphone started.
+  Future<bool> startVoiceInput({
+    String unavailableMessage = micUnavailableMessage,
+  }) async {
+    final started = await VoiceService.instance.startRecording();
+    if (!mounted) return started;
+    if (started) {
+      setState(() {
+        aiVoiceRecording = true;
+        listening = true;
+      });
+    } else {
+      showVoiceMessage(unavailableMessage);
+    }
+    return started;
+  }
+
+  /// Stops the answer recording and transcribes it.
+  ///
+  /// [onTranscript] runs inside `setState` with the trimmed, non-empty text.
+  /// [afterTranscribe] runs once transcription has finished, whether or not
+  /// anything was recognized. With [keepAudio] the answer audio also becomes
+  /// the playback [recordingPath].
+  Future<void> finishVoiceInput({
+    required void Function(String text) onTranscript,
+    VoidCallback? afterTranscribe,
+    bool keepAudio = true,
+    String noSpeech = noSpeechMessage,
+  }) async {
+    final path = await VoiceService.instance.stopRecording();
+    if (!mounted) return;
+    setState(() {
+      aiVoiceRecording = false;
+      listening = false;
+      transcribing = path != null;
+      if (keepAudio) recordingPath = path;
+    });
+    if (path == null) return;
+    final config = voiceState.aiConfig;
+    final transcribed = await AiService.instance.transcribeAudio(
+      filePath: path,
+      provider: config.provider,
+      endpoint: config.endpoint,
+      model: config.model,
+    );
+    if (!mounted) return;
+    final text = transcribed?.trim() ?? '';
+    setState(() {
+      transcribing = false;
+      if (text.isNotEmpty) onTranscript(text);
+    });
+    afterTranscribe?.call();
+    if (text.isEmpty) showVoiceMessage(noSpeech);
+  }
+
+  /// Starts a playback recording, replacing the previous one, or stops it.
+  Future<void> toggleRecording() async {
+    if (recording) {
+      final path = await VoiceService.instance.stopRecording();
+      if (mounted) {
+        setState(() {
+          recording = false;
+          recordingPath = path;
+        });
+      }
+      return;
+    }
+    await VoiceService.instance.deleteRecording(recordingPath);
+    final ready = await VoiceService.instance.startRecording();
+    if (!mounted) return;
+    setState(() {
+      recording = ready;
+      if (ready) recordingPath = null;
+    });
+    if (!ready) showVoiceMessage('无法使用麦克风录音；请检查系统权限。');
+  }
+
+  Future<void> playRecording() async {
+    final path = recordingPath;
+    if (path == null) return;
+    setState(() => playingRecording = true);
+    await VoiceService.instance.playRecording(
+      path,
+      onComplete: () {
+        if (mounted) setState(() => playingRecording = false);
+      },
+    );
+  }
+
+  Future<void> deleteRecording() async {
+    await VoiceService.instance.stopRecordingPlayback();
+    await VoiceService.instance.deleteRecording(recordingPath);
+    if (mounted) {
+      setState(() {
+        recordingPath = null;
+        playingRecording = false;
+      });
+    }
+  }
+
+  /// Releases the microphone and player; call from `dispose`. Unless
+  /// [keepRecording], the recorded attempt is deleted.
+  void disposeVoiceAnswer({required bool keepRecording}) {
+    final voice = VoiceService.instance;
+    voice.stopRecordingPlayback();
+    if (listening && !aiVoiceRecording) voice.stopListening();
+    if (aiVoiceRecording || recording) {
+      voice.stopRecording().then((path) {
+        if (!keepRecording) voice.deleteRecording(path);
+      });
+    }
+    if (!keepRecording) voice.deleteRecording(recordingPath);
+  }
+}
+
+/// Record / play back / delete buttons for [VoiceAnswerMixin]'s playback
+/// recorder.
+class RecordingControls extends StatelessWidget {
+  const RecordingControls({
+    super.key,
+    required this.recording,
+    required this.playing,
+    required this.hasRecording,
+    required this.onToggleRecording,
+    required this.onPlay,
+    required this.onDelete,
+  });
+
+  final bool recording;
+  final bool playing;
+  final bool hasRecording;
+
+  /// Null disables the record button.
+  final VoidCallback? onToggleRecording;
+  final VoidCallback onPlay;
+  final VoidCallback onDelete;
+
+  @override
+  Widget build(BuildContext context) {
+    return Row(
+      children: [
+        Expanded(
+          child: OutlinedButton.icon(
+            onPressed: onToggleRecording,
+            icon: Icon(
+              recording
+                  ? Icons.stop_circle_outlined
+                  : Icons.fiber_manual_record,
+            ),
+            label: Text(recording ? '停止录音' : '录音回听'),
+          ),
+        ),
+        if (hasRecording) ...[
+          const SizedBox(width: 8),
+          IconButton(
+            tooltip: playing ? '正在播放' : '回听录音',
+            onPressed: playing ? null : onPlay,
+            icon: const Icon(Icons.play_arrow),
+          ),
+          IconButton(
+            tooltip: '删除录音',
+            onPressed: onDelete,
+            icon: const Icon(Icons.delete_outline),
+          ),
+        ],
+      ],
+    );
+  }
+}