tts语音适配iOS

lib/package/chat_dash/src/widgets/message_list/message_list.dart

@@ -4,21 +4,15 @@ enum TtsState { playing, stopped, paused, continued }
 
 class ChartTTS {
   String voiceName;
-  String locale;
   double volume;
   double speechRate;
-  String language = "en-US";
+  String language = "zh-CN";
   static ChartTTS tts = ChartTTS();
 
-  ChartTTS(
-      {this.voiceName = "Karen",
-      this.locale = 'en-AU',
-      this.volume = 1.0,
-      this.speechRate = 1.0}) {
+  ChartTTS({this.voiceName = "zh", this.volume = 1.0, this.speechRate = 1.0}) {
     flutterTts.setLanguage(language);
     flutterTts.setVolume(volume);
     flutterTts.setSpeechRate(speechRate);
-    flutterTts.setVoice({"name": voiceName, "locale": locale});
   }
 
   final FlutterTts _flutterTts = FlutterTts();