Flutter - Firebase - 無法獲取數據

Question

這是我在社交媒體應用程序上的通知頁面，但是當我打開該頁面時，它沒有顯示任何內容，只是在工作 (circularProgress())，這意味着數據庫中沒有數據，但有數據。 它只是無法獲取該數據，您能幫我解決一下嗎？

我試圖更新所有內容。 我的flutter版本是1.24.0-3.0.pre

應用程序和數據庫之間的連接沒有問題，因為我可以在另一個頁面獲取另一個數據。

它是否相關我不知道但我收到此錯誤：

6.26.0 - [Firebase/Firestore][I-FST000001] WatchStream (6000010b0818) Stream 錯誤：“不可用：操作超時”[VERBOSE-2:profiler_metrics_ios.mm(186)] 檢索線程信息時出錯：(os/kern)無效的論點

這是我以前的代碼，與原始代碼相似，但不起作用。

import 'package:pga/pages/home.dart';
import 'package:pga/pages/post_screen.dart';
import 'package:pga/pages/profile.dart';
import 'package:pga/widgets/header.dart';
import 'package:pga/widgets/progress.dart';
import 'package:cached_network_image/cached_network_image.dart';
import 'package:cloud_firestore/cloud_firestore.dart';
import 'package:flutter/material.dart';
import 'package:timeago/timeago.dart' as timeago;

class ActivityFeed extends StatefulWidget {
  @override
  _ActivityFeedState createState() => _ActivityFeedState();
}

class _ActivityFeedState extends State<ActivityFeed> {
  getActivityFeed() async {
    QuerySnapshot snapshot = await activityFeedRef
        .doc(currentUser.id)
        .collection('feedItems')
        .orderBy('timestamp', descending: true)
        .limit(50)
        .get();
    List<ActivityFeedItem> feedItems = [];
    snapshot.docs.forEach((doc) {
      feedItems.add(ActivityFeedItem.fromDocument(doc));
      //print('Activity Feed Item: ${doc.data}');
    });
    return feedItems;
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      backgroundColor: Colors.white70,
      appBar: header(context, titleText: "Bildirimler"),
      body: Container(
          child: FutureBuilder(
        future: getActivityFeed(),
        builder: (context, snapshot) {
          if (!snapshot.hasData) {
            return circularProgress();
          } else {
            return ListView(
              children: snapshot.data,
            );
          }
        },
      )),
    );
  }
}

Widget mediaPreview;
String activityItemText;

class ActivityFeedItem extends StatelessWidget {
  final String username;
  final String userId;
  final String type; // 'like', 'follow', 'comment'
  final String mediaUrl;
  final String postId;
  final String userProfileImg;
  final String commentData;
  final Timestamp timestamp;

  ActivityFeedItem({
    this.username,
    this.userId,
    this.type,
    this.mediaUrl,
    this.postId,
    this.userProfileImg,
    this.commentData,
    this.timestamp,
  });

  factory ActivityFeedItem.fromDocument(DocumentSnapshot doc) {
    return ActivityFeedItem(
      username: doc['username'],
      userId: doc['userId'],
      type: doc['type'],
      postId: doc['postId'],
      userProfileImg: doc['userProfileImg'],
      commentData: doc['commentData'],
      timestamp: doc['timestamp'],
      mediaUrl: doc['mediaUrl'],
    );
  }

  showPost(context) {
    Navigator.push(
      context,
      MaterialPageRoute(
        builder: (context) => PostScreen(
          postId: postId,
          userId: userId, //currentUser.id,
        ),
      ),
    );
  }

  configureMediaPreview(context) {
    if (type == "like" || type == 'comment') {
      mediaPreview = GestureDetector(
        onTap: () => showPost(context),
        child: Container(
          height: 50.0,
          width: 50.0,
          child: AspectRatio(
              aspectRatio: 16 / 9,
              child: Container(
                decoration: BoxDecoration(
                  image: DecorationImage(
                    fit: BoxFit.cover,
                    image: CachedNetworkImageProvider(mediaUrl),
                  ),
                ),
              )),
        ),
      );
    } else {
      mediaPreview = Text('');
    }

    if (type == 'like') {
      activityItemText = "Gönderini Beğendi";
    } else if (type == 'follow') {
      activityItemText = "Seni Takip Ediyor";
    } else if (type == 'comment') {
      activityItemText = "Yorum Yaptı: $commentData";
    } else {
      activityItemText = "Error: Unknown type '$type'";
    }
  }

  @override
  Widget build(BuildContext context) {
    configureMediaPreview(context);

    return Padding(
      padding: EdgeInsets.only(bottom: 2.0),
      child: Container(
        color: Colors.white54,
        child: ListTile(
          title: GestureDetector(
            onTap: () => showProfile(context, profileId: userId),
            child: RichText(
              overflow: TextOverflow.ellipsis,
              text: TextSpan(
                  style: TextStyle(
                    fontSize: 14.0,
                    color: Colors.black,
                  ),
                  children: [
                    TextSpan(
                      text: username,
                      style: TextStyle(fontWeight: FontWeight.bold),
                    ),
                    TextSpan(
                      text: ' $activityItemText',
                    ),
                  ]),
            ),
          ),
          leading: CircleAvatar(
            backgroundImage: CachedNetworkImageProvider(userProfileImg),
          ),
          subtitle: Text(
            timeago.format(timestamp.toDate()),
            overflow: TextOverflow.ellipsis,
          ),
          trailing: mediaPreview,
        ),
      ),
    );
  }
}

showProfile(BuildContext context, {String profileId}) {
  Navigator.push(
      context,
      MaterialPageRoute(
          builder: (context) => Profile(
                profileId: profileId,
              )));
}

這是我根據@Lakshmi Narayanan 建議更新的代碼，但仍然無法正常工作。

import 'package:pga/pages/home.dart';
import 'package:pga/pages/post_screen.dart';
import 'package:pga/pages/profile.dart';
import 'package:pga/widgets/header.dart';
import 'package:pga/widgets/progress.dart';
import 'package:cached_network_image/cached_network_image.dart';
import 'package:cloud_firestore/cloud_firestore.dart';
import 'package:flutter/material.dart';
import 'package:timeago/timeago.dart' as timeago;

class ActivityFeed extends StatefulWidget {
  @override
  _ActivityFeedState createState() => _ActivityFeedState();
}

class _ActivityFeedState extends State<ActivityFeed> {
  List<ActivityFeedItem> feedItemsList = [];
  int feedCount = 0;

  getActivityFeed() async {
    QuerySnapshot snapshot = await activityFeedRef
        .doc(currentUser.id)
        .collection('feedItems')
        .orderBy('timestamp', descending: true)
        .limit(50)
        .get();
    List<ActivityFeedItem> feedItems = [];
    snapshot.docs.forEach((doc) {
      feedItems.add(ActivityFeedItem.fromDocument(doc));
    });
    return feedItems;
  }

  feedItems() {
    return Container(
      child: FutureBuilder(
        future: getActivityFeed(),
        builder: (context, snapshot) {
          if (!snapshot.hasData) {
            return circularProgress();
          } else {
            return ListView(
              children: snapshot.data,
            );
          }
        },
      ),
    );
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      backgroundColor: Colors.white70,
      appBar: header(context, titleText: "Bildirimler"),
      body: ListView(
        shrinkWrap: true,
        children: <Widget>[
          feedItems(),
        ],
      ),
    );
  }
}

Widget mediaPreview;
String activityItemText;

class ActivityFeedItem extends StatelessWidget {
  final String feedId;
  final String username;
  final String userId;
  final String type; // 'like', 'follow', 'comment'
  final String mediaUrl;
  final String postId;
  final String userProfileImg;
  final String commentData;
  final Timestamp timestamp;

  ActivityFeedItem({
    this.feedId,
    this.username,
    this.userId,
    this.type,
    this.mediaUrl,
    this.postId,
    this.userProfileImg,
    this.commentData,
    this.timestamp,
  });

  factory ActivityFeedItem.fromDocument(DocumentSnapshot doc) {
    return ActivityFeedItem(
        username: doc['username'],
        userId: doc['userId'],
        type: doc['type'],
        postId: doc['postId'],
        userProfileImg: doc['userProfileImg'],
        commentData: doc['commentData'],
        timestamp: doc['timestamp'],
        mediaUrl: doc['mediaUrl'],
        feedId: doc['feedId']);
  }

  showPost(context) {
    Navigator.push(
      context,
      MaterialPageRoute(
        builder: (context) => PostScreen(
          postId: postId,
          userId: userId, //currentUser.id,
        ),
      ),
    );
  }

  configureMediaPreview(context) {
    if (type == "like" || type == 'comment') {
      mediaPreview = GestureDetector(
        onTap: () => showPost(context),
        child: Container(
          height: 50.0,
          width: 50.0,
          child: AspectRatio(
              aspectRatio: 16 / 9,
              child: Container(
                decoration: BoxDecoration(
                  image: DecorationImage(
                    fit: BoxFit.cover,
                    image: CachedNetworkImageProvider(mediaUrl),
                  ),
                ),
              )),
        ),
      );
    } else {
      mediaPreview = Text('');
    }

    if (type == 'like') {
      activityItemText = "Hayalini Beğendi";
    } else if (type == 'follow') {
      activityItemText = "Seni Takip Ediyor";
    } else if (type == 'comment') {
      activityItemText = "Yorum Yaptı: $commentData";
    } else {
      activityItemText = "Error: Unknown type '$type'";
    }
  }

  @override
  Widget build(BuildContext context) {
    configureMediaPreview(context);

    return Padding(
      padding: EdgeInsets.only(bottom: 2.0),
      child: Container(
        color: Colors.white54,
        child: ListTile(
          title: GestureDetector(
            onTap: () => showProfile(context, profileId: userId),
            child: RichText(
              overflow: TextOverflow.ellipsis,
              text: TextSpan(
                  style: TextStyle(
                    fontSize: 14.0,
                    color: Colors.black,
                  ),
                  children: [
                    TextSpan(
                      text: username,
                      style: TextStyle(fontWeight: FontWeight.bold),
                    ),
                    TextSpan(
                      text: ' $activityItemText',
                    ),
                  ]),
            ),
          ),
          leading: CircleAvatar(
            backgroundImage: CachedNetworkImageProvider(userProfileImg),
          ),
          subtitle: Text(
            timeago.format(timestamp.toDate()),
            overflow: TextOverflow.ellipsis,
          ),
          trailing: mediaPreview,
        ),
      ),
    );
  }
}

showProfile(BuildContext context, {String profileId}) {
  Navigator.push(
      context,
      MaterialPageRoute(
          builder: (context) => Profile(
                profileId: profileId,
              )));
}

這是我的 Udemy 課程中的原始代碼。

import 'package:cached_network_image/cached_network_image.dart';
import 'package:cloud_firestore/cloud_firestore.dart';
import 'package:flutter/material.dart';
import 'package:fluttershare/pages/home.dart';
import 'package:fluttershare/pages/post_screen.dart';
import 'package:fluttershare/pages/profile.dart';
import 'package:fluttershare/widgets/header.dart';
import 'package:fluttershare/widgets/progress.dart';
import 'package:timeago/timeago.dart' as timeago;

class ActivityFeed extends StatefulWidget {
  @override
  _ActivityFeedState createState() => _ActivityFeedState();
}

class _ActivityFeedState extends State<ActivityFeed> {
  getActivityFeed() async {
    QuerySnapshot snapshot = await activityFeedRef
        .document(currentUser.id)
        .collection('feedItems')
        .orderBy('timestamp', descending: true)
        .limit(50)
        .getDocuments();
    List<ActivityFeedItem> feedItems = [];
    snapshot.documents.forEach((doc) {
      feedItems.add(ActivityFeedItem.fromDocument(doc));
      // print('Activity Feed Item: ${doc.data}');
    });
    return feedItems;
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      backgroundColor: Colors.orange,
      appBar: header(context, titleText: "Activity Feed"),
      body: Container(
          child: FutureBuilder(
        future: getActivityFeed(),
        builder: (context, snapshot) {
          if (!snapshot.hasData) {
            return circularProgress();
          }
          return ListView(
            children: snapshot.data,
          );
        },
      )),
    );
  }
}

Widget mediaPreview;
String activityItemText;

class ActivityFeedItem extends StatelessWidget {
  final String username;
  final String userId;
  final String type; // 'like', 'follow', 'comment'
  final String mediaUrl;
  final String postId;
  final String userProfileImg;
  final String commentData;
  final Timestamp timestamp;

  ActivityFeedItem({
    this.username,
    this.userId,
    this.type,
    this.mediaUrl,
    this.postId,
    this.userProfileImg,
    this.commentData,
    this.timestamp,
  });

  factory ActivityFeedItem.fromDocument(DocumentSnapshot doc) {
    return ActivityFeedItem(
      username: doc['username'],
      userId: doc['userId'],
      type: doc['type'],
      postId: doc['postId'],
      userProfileImg: doc['userProfileImg'],
      commentData: doc['commentData'],
      timestamp: doc['timestamp'],
      mediaUrl: doc['mediaUrl'],
    );
  }

  showPost(context) {
    Navigator.push(
      context,
      MaterialPageRoute(
        builder: (context) => PostScreen(
          postId: postId,
          userId: userId,
        ),
      ),
    );
  }

  configureMediaPreview(context) {
    if (type == "like" || type == 'comment') {
      mediaPreview = GestureDetector(
        onTap: () => showPost(context),
        child: Container(
          height: 50.0,
          width: 50.0,
          child: AspectRatio(
              aspectRatio: 16 / 9,
              child: Container(
                decoration: BoxDecoration(
                  image: DecorationImage(
                    fit: BoxFit.cover,
                    image: CachedNetworkImageProvider(mediaUrl),
                  ),
                ),
              )),
        ),
      );
    } else {
      mediaPreview = Text('');
    }

    if (type == 'like') {
      activityItemText = "liked your post";
    } else if (type == 'follow') {
      activityItemText = "is following you";
    } else if (type == 'comment') {
      activityItemText = 'replied: $commentData';
    } else {
      activityItemText = "Error: Unknown type '$type'";
    }
  }

  @override
  Widget build(BuildContext context) {
    configureMediaPreview(context);

    return Padding(
      padding: EdgeInsets.only(bottom: 2.0),
      child: Container(
        color: Colors.white54,
        child: ListTile(
          title: GestureDetector(
            onTap: () => showProfile(context, profileId: userId),
            child: RichText(
              overflow: TextOverflow.ellipsis,
              text: TextSpan(
                  style: TextStyle(
                    fontSize: 14.0,
                    color: Colors.black,
                  ),
                  children: [
                    TextSpan(
                      text: username,
                      style: TextStyle(fontWeight: FontWeight.bold),
                    ),
                    TextSpan(
                      text: ' $activityItemText',
                    ),
                  ]),
            ),
          ),
          leading: CircleAvatar(
            backgroundImage: CachedNetworkImageProvider(userProfileImg),
          ),
          subtitle: Text(
            timeago.format(timestamp.toDate()),
            overflow: TextOverflow.ellipsis,
          ),
          trailing: mediaPreview,
        ),
      ),
    );
  }
}

showProfile(BuildContext context, {String profileId}) {
  Navigator.push(
    context,
    MaterialPageRoute(
      builder: (context) => Profile(
        profileId: profileId,
      ),
    ),
  );
}

Answer 1

代碼沒有錯..

由於我也使用過此代碼（來自 Udemy 的課程）@Raşid 事情是如果用戶喜歡您的帖子，文檔將添加到雲 firestore 的提要集合中，然后活動提要通知將填充數據。

你如何測試這個？

1. 您喜歡自己的帖子並嘗試將其添加到活動提要中嗎

（要么）

2. 其他用戶喜歡你的帖子

Ans 1）Go到你的帖子。dart然后注釋掉（測試后取消注釋..）

// if (isNotPostOwner)

從 addLikeToActivityFeed() 和 removeLikeToActivityFeed() 然后檢查出來，

Ans 2）嘗試第一個，應該是這樣的。 否則，我別無選擇..

Answer 2

試着把這個，

feedItems(){
 return Container(
          child: FutureBuilder(
        future: getActivityFeed(),
        builder: (context, snapshot) {
          if (!snapshot.hasData) {
     ------->       return circularProgress();
          } else {
     ------->       return ListView(
              children: snapshot.data,
            );
          }
        },
      ),
);
}

在單獨的 function 中，然后嘗試調用它，即

 return Scaffold(
      
      body: ListView(
        shrinkWrap: true,
        children: <Widget>[   
          feedItems(),
        ],
      ),
    );
  }
}