我是 Swift 的新手。我一直无法下载 Firebase 词典并将它们转换为对象数组。
下面的语法我做错了什么？在过去的两天里，我一直在试图解决这个问题，但没有成功。下面给了我一个索引超出范围的错误。这是因为 Firebase Dictionary 尚未完成下载还是我的 for in 循环语法有缺陷？也许两者都有？谢谢。
// Array of Location Objects
var locationsArray:[Location] = [Location]()
var ref = Firebase(url: "<MYFIREBASEURL>")
var dictionaryOfRecommendations:[NSDictionary] = [NSDictionary]()
var currentlyConstructingLocation:Location = Location()
func getLocationData() {
let titleRef = self.ref.childByAppendingPath("events")
titleRef.observeSingleEventOfType(.Value, withBlock: { snapshot in
var tempDict = [NSDictionary]()
for item in snapshot.children {
let child = item as! FDataSnapshot
let dict = child.value as! NSDictionary
tempDict.append(dict)
}
self.dictionaryOfRecommendations = tempDict
})
// Parse data from Firebase
// Loop through each dictionary and assign values to location object
var index:Int
for index in 0...dictionaryOfRecommendations.count {
// Current Json dictionary
let jsonDictionary:NSDictionary = self.dictionaryOfRecommendations[index]
self.currentlyConstructingLocation.title = jsonDictionary["title"] as! String!
self.currentlyConstructingLocation.locationsLatitudeArray = jsonDictionary["latitude"] as! Double
self.currentlyConstructingLocation.locationsLongitudeArray = jsonDictionary["longitude"] as! Double
// Append to Locations Array and start new Location
self.locationsArray.append(currentlyConstructingLocation)
self.currentlyConstructingLocation = Location()
}
// Notify the MainViewController that the Locations are ready.
...
}
最佳答案
以下是根据 Jay 的有用指导针对上述问题更新的正确代码:
//下载事件位置数据的模型。
//Firebase reference
var ref = Firebase(url: "<MYFIREBASEURL")
var locationsArray:[Location] = [Location]()
var dictionaryOfRecommendations:[NSDictionary] = [NSDictionary]()
var currentlyConstructingLocation:Location = Location()
func getLocationData() {
let titleRef = self.ref.childByAppendingPath("events")
titleRef.observeSingleEventOfType(.Value, withBlock: { snapshot in
var tempDict = [NSDictionary]()
for item in snapshot.children {
let child = item as! FDataSnapshot
let dict = child.value as! NSDictionary
tempDict.append(dict)
}
self.dictionaryOfRecommendations = tempDict
self.ParseFirebaseData()
})
}
func ParseFirebaseData() {
// Parse data from Firebase
// Loop through each dictionary and assign values to location object
var index:Int
for index in 0...dictionaryOfRecommendations.count - 1 {
// Current Json dictionary
let jsonDictionary:NSDictionary = self.dictionaryOfRecommendations[index]
self.currentlyConstructingLocation.title = jsonDictionary["title"] as! String!
self.currentlyConstructingLocation.locationsLatitudeArray = jsonDictionary["latitude"] as! Double
self.currentlyConstructingLocation.locationsLongitudeArray = jsonDictionary["longitude"] as! Double
// Append to Locations Array and start new Location
self.locationsArray.append(currentlyConstructingLocation)
self.currentlyConstructingLocation = Location()
}
}
关于ios - 使用 Firebase 异步字典下载创建对象数组 (Swift)，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/37218247/