我不记得除了尝试使用云firestore运行StreamBuilder之外还做了什么更改，然后下面的错误开始出现。我对StreamBuilder进行了注解，但没有任何更改。

• • 我采取的步骤：

1.已运行flutter发布缓存修复
1.已清除Flutter
1.删除Cloud Firestore软件包，然后调用pub get，然后再次添加并再次运行pub get。**
软件包版本： Firebase _核心：^0.7.0云存储器_火灾存储器：^0.16.0
Flutter：Flutter1.22.5·通道稳定·https://github.com/flutter/flutter.git框架·修订版7891006299（6周前）·2020年12月10日11：54：40 -0800引擎·修订版ae90085a84工具·Dart 2.10.4
错误：

/C:/Users/yassin/Downloads/Programming%20files/Flutter/.pub-cache/hosted/pub.dartlang.org/cloud_firestore-0.16.0/lib/src/collection_reference.dart: Error: A file can't be part of more than one library.
Try moving the shared declarations into the libraries, or into a new library.
/C:/Users/yassin/Downloads/Programming%20files/Flutter/.pub-cache/hosted/pub.dartlang.org/cloud_firestore-0.16.0/lib/cloud_firestore.dart: Context: Used as a part in this library.
/C:/Users/yassin/Downloads/Programming%20files/Flutter/.pub-cache/hosted/pub.dartlang.org/cloud_firestore-0.16.0/lib/cloud_firestore.dart%20: Context: Used as a part in this library.
/C:/Users/yassin/Downloads/Programming%20files/Flutter/.pub-cache/hosted/pub.dartlang.org/cloud_firestore-0.16.0/lib/src/document_change.dart: Error: A file can't be part of more than one library.
Try moving the shared declarations into the libraries, or into a new library.
/C:/Users/yassin/Downloads/Programming%20files/Flutter/.pub-cache/hosted/pub.dartlang.org/cloud_firestore-0.16.0/lib/cloud_firestore.dart: Context: Used as a part in this library.
/C:/Users/yassin/Downloads/Programming%20files/Flutter/.pub-cache/hosted/pub.dartlang.org/cloud_firestore-0.16.0/lib/cloud_firestore.dart%20: Context: Used as a part in this library.
/C:/Users/yassin/Downloads/Programming%20files/Flutter/.pub-cache/hosted/pub.dartlang.org/cloud_firestore-0.16.0/lib/src/document_reference.dart: Error: A file can't be part of more than one library.
Try moving the shared declarations into the libraries, or into a new library.
/C:/Users/yassin/Downloads/Programming%20files/Flutter/.pub-cache/hosted/pub.dartlang.org/cloud_firestore-0.16.0/lib/cloud_firestore.dart: Context: Used as a part in this library.
/C:/Users/yassin/Downloads/Programming%20files/Flutter/.pub-cache/hosted/pub.dartlang.org/cloud_firestore-0.16.0/lib/cloud_firestore.dart%20: Context: Used as a part in this library.
/C:/Users/yassin/Downloads/Programming%20files/Flutter/.pub-cache/hosted/pub.dartlang.org/cloud_firestore-0.16.0/lib/src/document_snapshot.dart: Error: A file can't be part of more than one library.
Try moving the shared declarations into the libraries, or into a new library.
/C:/Users/yassin/Downloads/Programming%20files/Flutter/.pub-cache/hosted/pub.dartlang.org/cloud_firestore-0.16.0/lib/cloud_firestore.dart: Context: Used as a part in this library.
/C:/Users/yassin/Downloads/Programming%20files/Flutter/.pub-cache/hosted/pub.dartlang.org/cloud_firestore-0.16.0/lib/cloud_firestore.dart%20: Context: Used as a part in this library.
/C:/Users/yassin/Downloads/Programming%20files/Flutter/.pub-cache/hosted/pub.dartlang.org/cloud_firestore-0.16.0/lib/src/field_value.dart: Error: A file can't be part of more than one library.
Try moving the shared declarations into the libraries, or into a new library.
/C:/Users/yassin/Downloads/Programming%20files/Flutter/.pub-cache/hosted/pub.dartlang.org/cloud_firestore-0.16.0/lib/cloud_firestore.dart: Context: Used as a part in this library.
/C:/Users/yassin/Downloads/Programming%20files/Flutter/.pub-cache/hosted/pub.dartlang.org/cloud_firestore-0.16.0/lib/cloud_firestore.dart%20: Context: Used as a part in this library.
/C:/Users/yassin/Downloads/Programming%20files/Flutter/.pub-cache/hosted/pub.dartlang.org/cloud_firestore-0.16.0/lib/src/firestore.dart: Error: A file can't be part of more than one library.
Try moving the shared declarations into the libraries, or into a new library.
/C:/Users/yassin/Downloads/Programming%20files/Flutter/.pub-cache/hosted/pub.dartlang.org/cloud_firestore-0.16.0/lib/cloud_firestore.dart: Context: Used as a part in this library.
/C:/Users/yassin/Downloads/Programming%20files/Flutter/.pub-cache/hosted/pub.dartlang.org/cloud_firestore-0.16.0/lib/cloud_firestore.dart%20: Context: Used as a part in this library.
/C:/Users/yassin/Downloads/Programming%20files/Flutter/.pub-cache/hosted/pub.dartlang.org/cloud_firestore-0.16.0/lib/src/query.dart: Error: A file can't be part of more than one library.
Try moving the shared declarations into the libraries, or into a new library.
/C:/Users/yassin/Downloads/Programming%20files/Flutter/.pub-cache/hosted/pub.dartlang.org/cloud_firestore-0.16.0/lib/cloud_firestore.dart: Context: Used as a part in this library.
/C:/Users/yassin/Downloads/Programming%20files/Flutter/.pub-cache/hosted/pub.dartlang.org/cloud_firestore-0.16.0/lib/cloud_firestore.dart%20: Context: Used as a part in this library.
/C:/Users/yassin/Downloads/Programming%20files/Flutter/.pub-cache/hosted/pub.dartlang.org/cloud_firestore-0.16.0/lib/src/query_document_snapshot.dart: Error: A file can't be part of more than one library.
Try moving the shared declarations into the libraries, or into a new library.
/C:/Users/yassin/Downloads/Programming%20files/Flutter/.pub-cache/hosted/pub.dartlang.org/cloud_firestore-0.16.0/lib/cloud_firestore.dart: Context: Used as a part in this library.
/C:/Users/yassin/Downloads/Programming%20files/Flutter/.pub-cache/hosted/pub.dartlang.org/cloud_firestore-0.16.0/lib/cloud_firestore.dart%20: Context: Used as a part in this library.
/C:/Users/yassin/Downloads/Programming%20files/Flutter/.pub-cache/hosted/pub.dartlang.org/cloud_firestore-0.16.0/lib/src/query_snapshot.dart: Error: A file can't be part of more than one library.
Try moving the shared declarations into the libraries, or into a new library.
/C:/Users/yassin/Downloads/Programming%20files/Flutter/.pub-cache/hosted/pub.dartlang.org/cloud_firestore-0.16.0/lib/cloud_firestore.dart: Context: Used as a part in this library.
/C:/Users/yassin/Downloads/Programming%20files/Flutter/.pub-cache/hosted/pub.dartlang.org/cloud_firestore-0.16.0/lib/cloud_firestore.dart%20: Context: Used as a part in this library.
/C:/Users/yassin/Downloads/Programming%20files/Flutter/.pub-cache/hosted/pub.dartlang.org/cloud_firestore-0.16.0/lib/src/snapshot_metadata.dart: Error: A file can't be part of more than one library.
Try moving the shared declarations into the libraries, or into a new library.
/C:/Users/yassin/Downloads/Programming%20files/Flutter/.pub-cache/hosted/pub.dartlang.org/cloud_firestore-0.16.0/lib/cloud_firestore.dart: Context: Used as a part in this library.
/C:/Users/yassin/Downloads/Programming%20files/Flutter/.pub-cache/hosted/pub.dartlang.org/cloud_firestore-0.16.0/lib/cloud_firestore.dart%20: Context: Used as a part in this library.
/C:/Users/yassin/Downloads/Programming%20files/Flutter/.pub-cache/hosted/pub.dartlang.org/cloud_firestore-0.16.0/lib/src/transaction.dart: Error: A file can't be part of more than one library.
Try moving the shared declarations into the libraries, or into a new library.
/C:/Users/yassin/Downloads/Programming%20files/Flutter/.pub-cache/hosted/pub.dartlang.org/cloud_firestore-0.16.0/lib/cloud_firestore.dart: Context: Used as a part in this library.
/C:/Users/yassin/Downloads/Programming%20files/Flutter/.pub-cache/hosted/pub.dartlang.org/cloud_firestore-0.16.0/lib/cloud_firestore.dart%20: Context: Used as a part in this library.
/C:/Users/yassin/Downloads/Programming%20files/Flutter/.pub-cache/hosted/pub.dartlang.org/cloud_firestore-0.16.0/lib/src/utils/codec_utility.dart: Error: A file can't be part of more than one library.
Try moving the shared declarations into the libraries, or into a new library.
/C:/Users/yassin/Downloads/Programming%20files/Flutter/.pub-cache/hosted/pub.dartlang.org/cloud_firestore-0.16.0/lib/cloud_firestore.dart: Context: Used as a part in this library.
/C:/Users/yassin/Downloads/Programming%20files/Flutter/.pub-cache/hosted/pub.dartlang.org/cloud_firestore-0.16.0/lib/cloud_firestore.dart%20: Context: Used as a part in this library.
/C:/Users/yassin/Downloads/Programming%20files/Flutter/.pub-cache/hosted/pub.dartlang.org/cloud_firestore-0.16.0/lib/src/write_batch.dart: Error: A file can't be part of more than one library.
Try moving the shared declarations into the libraries, or into a new library.
/C:/Users/yassin/Downloads/Programming%20files/Flutter/.pub-cache/hosted/pub.dartlang.org/cloud_firestore-0.16.0/lib/cloud_firestore.dart: Context: Used as a part in this library.
/C:/Users/yassin/Downloads/Programming%20files/Flutter/.pub-cache/hosted/pub.dartlang.org/cloud_firestore-0.16.0/lib/cloud_firestore.dart%20: Context: Used as a part in this library.

FAILURE: Build failed with an exception.

* Where:
Script 'C:\Users\yassin\Downloads\Programming files\Flutter\packages\flutter_tools\gradle\flutter.gradle' line: 904

* What went wrong:
Execution failed for task ':app:compileFlutterBuildDebug'.
> Process 'command 'C:\Users\yassin\Downloads\Programming files\Flutter\bin\flutter.bat'' finished with non-zero exit value 1

* Try:
Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output. Run with --scan to get full insights.

* Get more help at https://help.gradle.org

BUILD FAILED in 12s
Exception: Gradle task assembleDebug failed with exit code 1

更新1：当前被注解的流，但在错误出现之前我已经调用了。

Future<List<QuerySnapshot>> displayLocations() async {
        final List<DocumentSnapshot> documents = [];
        _firebaseFirestore
            .collection('locations')
            .get()
            .then((QuerySnapshot querySnapshot) => {
                  querySnapshot.docs.forEach((doc) {
                    documents.add(doc);
                    return documents;
                  })
                });
      }

 @override
  Widget build(BuildContext context) {
    return StreamBuilder<QuerySnapshot>(
      stream: FirebaseFirestore.instance.collection('locations').snapshots(),
      builder: (BuildContext context, AsyncSnapshot<QuerySnapshot> snapshot) {
        if (snapshot.hasError) {
          return Text('Something went wrong');
        }

        if (snapshot.connectionState == ConnectionState.waiting) {
          return Text("Loading");
        }

        return ListView(
          children: snapshot.data.docs.map((DocumentSnapshot document) {
            return ListTile(
              title: Text(
                  document.data()['locationName'] ?? 'Unable to retrieve data'),
            );
          }).toList(),
        );
      },
    );
  }