togglePlayState method
      
void
togglePlayState()
      
     
    
切换播放状态
Toggle between play and pause states.
Implementation
void togglePlayState() {
  final playState = playStateNotifier.value;
  logi("togglePlayState: $playState");
  if (playState == FlutterAvpdef.started) {
    pause();
  } else if (playState == FlutterAvpdef.completion) {
    replay();
  } else if (_isPrepared) {
    play();
  }
}