Swift 3 - viewdidloadの関数が完全に実行されていない

Question

viewDidLoadの関数を使用して配列を追加し、その配列を他の関数で使用しています。私のプログラムを実行すると、の関数は完全に実行されません。私はこれを手伝ってください。

私のコード： -

override func viewDidLoad() { 
    super.viewDidLoad() 
    self.getAllUsers() 
    self.fetchData() 
} 
func getAllUsers(){ 
    ref = Database.database().reference() 
    ref.child("users").observe(.value, with: { (snapshot) in 
     if let result = snapshot.children.allObjects as? [DataSnapshot] { 
      for child in result { 
       var userid = child.key 
       print(userid) 
       self.uuid.append(userid) 
      } 
     } 
     if self.uuid.contains((Auth.auth().currentUser?.uid)!) { 
      print("Id matched") 
     } 
    }) 

    let array = ["Frodo", "sam", "wise", "gamgee"] 
    let randomIndex = Int(arc4random_uniform(UInt32(array.count))) 
    print(array[randomIndex]) 

} 
func fetchData() { 
    let randomIndex = Int(arc4random_uniform(UInt32(uuid.count))) 
    print(uuid[randomIndex]) 
    print(randomIndex) 
    randomI = randomIndex 
    Message.downloadAllMessages(forUserID: uuid[randomIndex], completion: {[weak weakSelf = self] (message) in 
     weakSelf?.items.append(message) 
     weakSelf?.items.sort{ $0.timestamp < $1.timestamp } 
     DispatchQueue.main.async { 
      if let state = weakSelf?.items.isEmpty, state == false { 
       weakSelf?.tableView.reloadData() 
       weakSelf?.tableView.scrollToRow(at: IndexPath.init(row: self.items.count - 1, section: 0), at: .bottom, animated: false) 
      } 
     } 
    }) 
    Message.markMessagesRead(forUserID: uuid[randomIndex]) 
} 

Answer 1

は完了ブロックの後self.fetchData()を呼び出すようにしてください。あなたはcompeletionの前にself.fetchData()に電話しています。

override func viewDidLoad() { 
    super.viewDidLoad() 
    self.getAllUsers() 

} 
func getAllUsers(){ 
    ref = Database.database().reference() 
    ref.child("users").observe(.value, with: { (snapshot) in 
     if let result = snapshot.children.allObjects as? [DataSnapshot] { 
      for child in result { 
       var userid = child.key 
       print(userid) 
       self.uuid.append(userid) 
      } 
     } 

     if self.uuid.contains((Auth.auth().currentUser?.uid)!) { 
      print("Id matched") 
     } 
     self.fetchData()// call your method after compeletion block 
    }) 

    let array = ["Frodo", "sam", "wise", "gamgee"] 
    let randomIndex = Int(arc4random_uniform(UInt32(array.count))) 
    print(array[randomIndex]) 

} 
func fetchData() { 
    let randomIndex = Int(arc4random_uniform(UInt32(uuid.count))) 
    print(uuid[randomIndex]) 
    print(randomIndex) 
    randomI = randomIndex 
    Message.downloadAllMessages(forUserID: uuid[randomIndex], completion: {[weak weakSelf = self] (message) in 
     weakSelf?.items.append(message) 
     weakSelf?.items.sort{ $0.timestamp < $1.timestamp } 
     DispatchQueue.main.async { 
      if let state = weakSelf?.items.isEmpty, state == false { 
       weakSelf?.tableView.reloadData() 
       weakSelf?.tableView.scrollToRow(at: IndexPath.init(row: self.items.count - 1, section: 0), at: .bottom, animated: false) 
      } 
     } 
    }) 
    Message.markMessagesRead(forUserID: uuid[randomIndex]) 
}