Swift

Question

我正在尝试从我从数据库中获取的字典 [String : Any] 中删除阻止用户。首先，我获取当前用户已阻止的 UID 列表：

var updatedBlockList: Any?
func findBlockUsers() {
    // find current users list of blocked users
    guard let currentUserUid = Auth.auth().currentUser?.uid else { return }

    let blockedUsers = Database.database().reference().child("users").child(currentUserUid)

    blockedUsers.observeSingleEvent(of: .value, with: { (snapshot) in
        guard let userIdsDictionary = snapshot.value as? [String: Any] else { return }
        userIdsDictionary.forEach({ (key, value) in
            guard let userDictionary = value as? [String: Any] else { return }

            var blockedList : Any
            blockedList = userDictionary.keys

            print(blockedList)

            self.updateBlockList(blockedList: blockedList)

        })
    })
}

func updateBlockList(blockedList: Any) {
    updatedBlockList = blockedList
    print(updatedBlockList)
}

如果我打印 updatedBlockList，我得到：["gdqzOXPWaiaTn93YMJBEv51UUUn1"、"RPwVj59w8pRFLf55VZ6LGX6G2ek2"、"xmigo8CPzhNLlXN4oTHMpGo7f213"]

我现在想获取这些 UID（这将是 UserIdsDictionary 中的键，并在我拉出所有用户后删除它们：

fileprivate func fetchAllUserIds() {

    let ref = Database.database().reference().child("users")
        ref.observeSingleEvent(of: .value, with: { (snapshot) in
        guard let userIdsDictionary = snapshot.value as? [String: Any] else { return }

        userIdsDictionary.forEach({ (key, value) in

            // attempting to remove the blocked users here without any luck
            var updatedKey = key as String?
            updatedKey?.remove(at: self.updatedBlockList as! String.Index)
            print(updatedKey!)

            guard let  userDictionary = value as? [String: Any] else { return }

            let user = User(uid: key, dictionary: userDictionary)
            self.fetchPostsWithUser(user: user)
        })

    }) { (err) in
        print("Failed to fetch following user ids:", err)
    }

}

我在尝试删除时遇到此错误：无法将类型 'Swift.Dictionary.Keys' (0x1de2f6b78) 的值转换为 'Swift.String.Index'

我确定我的做法是错误的，但我知道我已经接近了。最终目标是获取被阻止的用户 UID 并将其从字典中删除。任何帮助将不胜感激！！

Answer 1

您在 userIdsDictionary 上的 forEach 循环在这里是错误的方法，因此我不会尝试修复该代码，而是使用不同的方法并循环遍历 updatedBlockList

for item in updatedBlockList {
    if let userID = item as? String {
        userIdsDictionary.removeValue(forKey: userID)
    }
}

Answer 2

对于任何想知道的人，这里是为使其工作所做的最后更改。

var updatedBlockList = [String]()

func findBlockUsers() {
    // find current users list of blocked users
    guard let currentUserUid = Auth.auth().currentUser?.uid else { return }

    let blockedUsers = Database.database().reference().child("users").child(currentUserUid)

    blockedUsers.observeSingleEvent(of: .value, with: { (snapshot) in
        guard let userIdsDictionary = snapshot.value as? [String: Any] else { return }
        userIdsDictionary.forEach({ (key, value) in
            guard let userDictionary = value as? [String: Any] else { return }

            let blockedList = Array(userDictionary.keys)

            print(blockedList)

            self.updateBlockList(blockedList: blockedList)

        })
    })
}

func updateBlockList(blockedList: [String]) {
    updatedBlockList = blockedList
    print(updatedBlockList)
}

fileprivate func fetchAllUserIds() {

    let ref = Database.database().reference().child("users")
        ref.observeSingleEvent(of: .value, with: { [weak self] (snapshot) in
        guard var userIdsDictionary = snapshot.value as? [String: Any], let self = self else { return }

        for item in self.updatedBlockList {
            userIdsDictionary.removeValue(forKey: item)
        }

        userIdsDictionary.forEach({ (key, value) in

            guard let  userDictionary = value as? [String: Any] else { return }
            let user = User(uid: key, dictionary: userDictionary)
            self.fetchPostsWithUser(user: user)
        })
    }) { (err) in
        print("Failed to fetch following user ids:", err)
    }

}

Swift - 从字典 [String : Any] 中删除键和值

Swift - Remove key and values from dictionary [String : Any]

string

dictionary

any