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我可以从我的应用程序中成功读取和写入云 Firestore 数据库。但是，当在 iOS 模拟器（或真实设备）上运行时，我无法通过 Riverpod 或标准 StreamBuilder 监听流以实时更改文档。收听流时不会引发错误或异常。流存在，只是其中没有数据。在 Android 模拟器上运行时不存在此问题。

流提供者

final athletePosStreamProvider = StreamProvider<GPSPoint>((ref) {
  final _fsDB = FirebaseFirestore.instance;

  print('Provider is active');

  return _fsDB.collection('Athlete1').doc('currentPosition').snapshots().map((document) {
    print('stream data found');
    return GPSPoint.fromFSMap(document.data());
  });
});

流听：

final athletePos = Provider<GPSPoint>((ref) {
  GPSPoint _curPos;

  print('athletePos is active');

  Stream _docStream = FirebaseFirestore.instance.collection('Athlete1').doc('currentPosition').snapshots();

  if (_docStream.isBroadcast == true) {
    print('Stream is broadcasting');
  }

  _docStream.listen((event) {
    print('athletePos stream event received');
    _curPos = GPSPoint.fromFSMap(event.data());
  });

  return _curPos;
});

在这两种情况下，第一个 print 语句都会触发，但第二个 print 语句永远不会在 iOS 上触发。它将在 Android 上正常工作。

pubspec.yaml    
cloud_firestore: ^0.14.3+1
flutter_riverpod: ^0.12.1

扑医生

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