在 SWIFT 4.1 中从 Firebase 检索数据时，"下标"和"无法调用"非函数类型"AnyObject"的值时出现歧义使用

Question

我正在改变我发布和检索 firebase CLLocationCoordinated2D 的方式，从每个值一个帖子到一个包含所有值的帖子，所以我找到了这篇文章，我想在我自己的代码中实现它。从 Firebase 检索数据并存储为地图上的注释。 我在常量日期、时间、纬度、经度和描述上遇到了标题中提到的错误。 我还在学习Firebase，所以任何解释都会非常有帮助。这是我收到错误的函数。

   func displayAnnotations() {
        let ref = Database.database().reference()
        ref.child("Sightings").observe(.childAdded, with: { (snapshot) in
            let date = (snapshot.value as AnyObject?)!("Date") as! String?
            let time = (snapshot.value as AnyObject)!("Time") as! String?
            let latitude = (snapshot.value as AnyObject)!("Latitude") as! String?
            let longitude = (snapshot.value as AnyObject?)!("Longitude") as! String?
            let desc = (snapshot.value as AnyObject?)!("Description") as! String?
            let annotation = MKPointAnnotation()
            annotation.coordinate = CLLocationCoordinate2D(latitude: (Double(latitude!))!, longitude: (Double(longitude!))!)
            annotation.title = date
            annotation.subtitle = time
            self.mapView.addAnnotation(annotation)
        })}

这是发布功能：

func post() {
        let date = dateLabel.text
        let time = timeLabel.text
        let latitude = latitudeLabel.text
        let longitude = longitudeLabel.text
        let sightingDescription = descriptionLabel.text
        let post: [String:String] = ["Date" : date as AnyObject,
                                          "Time" : time as AnyObject,
                                          "Latitude" : latitude as AnyObject,
                                          "Longitude" : longitude as AnyObject,
                                          "Description" : sightingDescription as AnyObject]
        var ref: DatabaseReference!
        ref = Database.database().reference()
        ref.child("Sightings").childByAutoId().setValue(post)
    }

仅仅是因为它是为 swift 4.1 之前的版本编写的吗？

Answer 1

您将[]更改为()

let dic = snapshot.value as! [String:String]
let date = dic["Date"] 
let time = dic["Time"]   
let latitude = dic["Latitude"] 
let longitude = dic["Longitude"]  
let desc = dic["Description"]