我是在我的firstviewController中使用firebase的新手,当我导入firebasatedAtabase时,它xcode xcode imediatiatiat imediatiat imediat imediat在第13行(FirstViewController的类别(上显示一个错误。/Users/admin/Documents/shneckleclicker2/shneckleclicker2/FirstViewController.swift:13:7: Class 'FirstViewController' has no initializers
但是,当我删除该行var ref: FIRDatabaseReference
时,错误失败。
FirstViewController中的代码:
import UIKit
import NotificationCenter
import FirebaseDatabase
class FirstViewController: UIViewController {
var ref: FIRDatabaseReference
让参考:firdatabasereference!需要强制解开
xcode显示错误,因为" ref"不是初始化的。您可以替换
var ref: FIRDatabaseReference
var ref: FIRDatabaseReference? = nil
"?"表明它是一个可选的,因此您需要在这样使用之前将其解开:
let reference = ref! // Assigning Value
setReference(ref!) // Calling a Method