我试图解决这个简单的问题，但我肯定不明白我做错了什么。
我有两个视图控制器，LoginVC和HomeVC。在LoginVC上进行身份验证后，用户进入HomeVC，在那里我有一个函数，检查用户是否登录并从Firebase获取数据。
当HomeVC出现时，UIImageView会立即从FirebaseStorage获取照片，但所有标签会在1秒后获取数据。

override func viewDidLoad() {
    super.viewDidLoad()

    checkIfUserLogedIn()
}

//check if loged in and fill information
func checkIfUserLogedIn() {
    if FirebaseAuth.Auth.auth().currentUser?.uid != nil {
        let uid = FirebaseAuth.Auth.auth().currentUser?.uid
        FirebaseDatabase.Database.database().reference().child("users").child(uid!).observeSingleEvent(of: .value, with: { (DataSnapshot) in
             if let dictionary =  DataSnapshot.value as? [String: String] {
                 //update labels
                 self.nameLabel.text = dictionary["name"]
                 self.lastNameLabel.text = dictionary["lastName"]
                 self.ageLabel.text = dictionary["age"]
                 self.cityCountryLabel.text = dictionary ["cityCountry"]
                 self.phoneNumberLabel.text = dictionary ["phoneNumber"]
            }
        })

        //fetch photo to the UIImageView
        let storageRef = Storage.storage().reference(withPath: "usersPhoto/\(uid!).jpg")
        let placeHolder = UIImage(named: "placeholder.jpg")

        imageViewPhoto.sd_setImage(with: storageRef, placeholderImage: placeHolder)
        imageViewPhoto.contentMode = .scaleAspectFill
        imageViewPhoto.layer.cornerRadius = 25
        imageViewPhoto.layer.shadowColor = #colorLiteral(red: 0.8374180198, green: 0.8374378085, blue: 0.8374271393, alpha: 1)
        imageViewPhoto.layer.shadowOffset = CGSize(width: 0, height: 0)
        imageViewPhoto.layer.shadowRadius = 5
        imageViewPhoto.layer.shadowOpacity = 0.4
        imageViewPhoto.layer.backgroundColor = #colorLiteral(red: 1, green: 1, blue: 1, alpha: 1)
        imageViewPhoto.layer.borderColor = #colorLiteral(red: 0.921431005, green: 0.9214526415, blue: 0.9214410186, alpha: 1)
        imageViewPhoto.layer.borderWidth = 0.5
    } else {
        return
    }
}

我试探着：

DispatchQueue.main.async {
    //upadte labels
    self.nameLabel.text = dictionary["name"]
    self.lastNameLabel.text = dictionary["lastName"]
    self.ageLabel.text = dictionary["age"]
    self.cityCountryLabel.text = dictionary ["cityCountry"]
    self.phoneNumberLabel.text = dictionary ["phoneNumber"]
}

我也试过：

DispatchQueue.main.async(execute: {
    //upadte labels
    self.nameLabel.text = dictionary["name"]
    self.lastNameLabel.text = dictionary["lastName"]
    self.ageLabel.text = dictionary["age"]
    self.cityCountryLabel.text = dictionary ["cityCountry"]
    self.phoneNumberLabel.text = dictionary ["phoneNumber"]
}
})