Swift-从字典[String：Any]中删除键和值

Question

我正在尝试从数据库中抓取的词典[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，则会得到：[“ gdqzOXPWaiaTn93YMJBEv51UUUn1”，“ RPwVj59w8pRFLf55VZ6LGX6G2ek2”，“ xmigo8CPzhNLlXN4oTHMpGo7f213”]

我现在想获取那些UID（这将是UserIdsDictionary中的键，并在拉所有用户之后将其删除：

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)
    }

}

尝试删除时收到此错误：无法将类型'Swift.Dictionary.Keys'（0x1de2f6b78）的值强制转换为'Swift.String.Index'

我确定我会采用错误的方式，但是我知道我已经接近了。最终目标是获取被阻止用户的UID并将其从词典中删除。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，因此与其尝试修复该代码，我不使用固定方法并在updatedBlockList上循环

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，这是为了使其工作而进行的最终更改。

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)
    }

}