Flutter Just Audio playbackEvent

问题

I am using a package called Just Audio in my Flutter app. It provides an playBackEvent: playbackEvent.currentPosition which shows the time position that has been played in the Audio file. However I'm a little new to Dart and don't really understand how to subscribe a listener to this event so that I can do something with the changing values.

What I want to do is run a function which sets state when the value changes so I can show the progress and let the users know how far through the Audio file they are at that moment.

Can someone please explain to me how I should do this?

Any help would be much appreciated.

回答1:

A complete sample available here.

 StreamBuilder<Duration>(
            stream: _player.durationStream,
            builder: (context, snapshot) {
              final duration = snapshot.data ?? Duration.zero;
              return StreamBuilder<Duration>(
                stream: _player.getPositionStream(),
                builder: (context, snapshot) {
                  var position = snapshot.data ?? Duration.zero;
                  if (position > duration) {
                    position = duration;
                  }
                  return SeekBar(
                    duration: duration,
                    position: position,
                    onChangeEnd: (newPosition) {
                      _player.seek(newPosition);
                    },
                  );
                },
              );
            },
          ),

来源：https://stackoverflow.com/questions/60165915/flutter-just-audio-playbackevent