我在嵌套字典中访问密钥时遇到问题 .
在我的ViewDidLoad中,我已经定义了字典(currentDots)来存储String键和任何对象作为值:
ViewDidLoad
var currentDots = Dictionary<String, Any>()
这里它正在侦听回调中的对象并将字典写入currentDots字典..没问题,工作正常:
Query Handler
func setupQueryHandle(query: GFCircleQuery) {
var queryHandle = query.observeEventType(GFEventTypeKeyEntered, withBlock: { (key: String!, location: CLLocation!) in
var dotRef = firebaseReference.childByAppendingPath("dotLocation/\(key)")
dotRef.observeEventType(.Value, withBlock: { snapshot in
self.currentDots[key] = ["name": snapshot.value.objectForKey("dot_name") , "description": snapshot.value.objectForKey("dot_description"), "range": snapshot.value.objectForKey("range"), "location": location ]**
self.annotateDot(key)
}, withCancelBlock: { error in
println(error.description)
})
})
}
但是在这里,我无法解析Dictionary中的键,尽管上面的语句将字典写为Dictionary对象,但编译器会跳过if temp是Dictionary语句:
Annotate Dot
func annotateDot(key: String) {
if currentDots[key] as Any? != nil {
let temp = currentDots[key]!
println("Current dot is... \(temp)")
if temp is Dictionary<String,Any> {
println(currentDots[key]!)
let dotDictionary = currentDots[key] as Dictionary <String, AnyObject>
let dotName = dotDictionary["name"] as String
println(dotName)
}
}
}
我在“if”语句之前得到的println输出(“当前点是”):
403986692:[范围:可选(500),描述:可选(这是一个测试点!),名称:可选(mudchute DLR),位置:可选(<51.49173972,-0.01396433> / - 0.00m(速度-1.00 mps /当然-1.00)@ 17/12/2014 15:12:09格林威治标准时间)],
..which建议查找currentDots [403986692]应该只返回一个字典而不是 . 当我通过临时对象跟踪时,在Xcode中显示为类型:
([String:protocol <>?])
有谁知道我在这里做错了什么?非常感谢您的帮助 .
谢谢!
1 回答
尝试更改
currentDots
的声明,因为我认为问题的一部分与你做Any
可选有关,这不是一个好主意:然后尝试以下
annotateDot(key: String)
: