devicesChangedEventStream on IOS ,not work!

[brotherdang]

AudioSession.instance.then((session) { session.setActive(true); subscription4DeviceRemoved = session.devicesChangedEventStream.listen((event) async { if (ref.read(seriesProvider(seriesID))?.model?.viewEpisode != episode?.index || episode?.unlock == false) return;

    var devices = await session.getDevices();
    LogUtils.printLog("eventStream 11", "devices.length = ${devices.length}");
    context.showToast("音频设备个数${devices.length}");