Question

在聊天集合的Firestore中，有几个文档：

文档1：
receiverID：“Leo”
消息：“你好”
...

文档2：
receiverID：“彼得”
消息：“谢谢你帮助我” ...

文件3：
receiverID：“Leo”
消息：“我很高兴帮助你进入堆栈溢出”

在我创建收件箱时，目前它正在向我展示用户的集合视图，例如“Leo”，“Peter”，“Leo”。我想在我的收件箱中只显示Leo和Peter这样的独特用户，如何进行客户端过滤以实现结果？

以下是我在InboxViewController中的代码

func numberOfSections(in collectionView: UICollectionView) -> Int {
    return 1
}
func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int{
    return chats.count
}

func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell{
    let cell = collectionView.dequeueReusableCell(withReuseIdentifier: cellIdentifier, for: indexPath) as! InboxCollectionViewCell
    cell.inboxMessage.text = chats[indexPath.row].receiverID
    return cell
}


func loadPosts() {
    let senderIDNumber = Auth.auth().currentUser?.uid
    let chatsRef = db.collection("chats")
    chatsRef.whereField("senderID", isEqualTo: senderIDNumber!)
        .addSnapshotListener { querySnapshot, error in
            guard let documents = querySnapshot?.documents else {
                print("Error fetching documents: \(error!)")
                return
            }
            for document in documents {
                let messageText = document.data()["message"] as? String
                let senderIDNumber = document.data()["senderID"] as? String
                let receiverIDNumber = document.data()["receiverID"] as? String
                let timestamp = document.data()["timestamp"] as? String
                let conversationsCounter = document.data()["conversationsCounter"] as? Int
                let chat = Chat(messageTextString: messageText!, senderIDNumber: senderIDNumber!, receiverIDNumber: receiverIDNumber!, timeStampString: timestamp!, conversationsCounterInt: conversationsCounter!)
                self.chats.append(chat)
                print(self.chats)
                self.collectionView.reloadData()
            }
    }
}

}

目前，我在收件箱中收到此信息：
狮子座
彼得
利奥

我只想看到名字
狮子座
彼得
删除重复项。

Answer 1

在聊天中检查是否存在receiveid

if chats.contains(where: { $0. receiverIDNumber == receiverIDNumber }) {
    {
    }else{
    let chat = Chat(messageTextString: messageText!, senderIDNumber: senderIDNumber!, receiverIDNumber: receiverIDNumber!, timeStampString: timestamp!, conversationsCounterInt: conversationsCounter!)
            self.chats.append(chat)
    }

客户端过滤字典以获得唯一值

1 个答案: