swift - NSFastEnumerationIterator.Element(又名 Any)不符合协议(protocol) 'AnyObject'

Question

升级到 Xcode 8 (Swift 3) 后，我的 Firebase 查询出现错误 NSFastEnumerationIterator.Element (aka Any) does not conform to protocol 'AnyObject' 当我尝试遍历快照:

for child in snapshot.children {
                if (child as AnyObject).value!["postedBy"] != nil { 

Xcode 将 child.value["postedBy"] 更改为 (child as AnyObject).value!["postedBy"] 引发错误。然后我尝试将其更改为

((child as AnyObject).value as? NSDictionary)["postedBy"] != nil 

但随后它会抛出一个不同的错误Binary operator != cannot be applied to operands of type _ and _

我的方向是否正确？任何帮助将不胜感激。

谢谢!!

最终解决方案:

for child in snapshot.children{
                if let postedBy = (snapshot.value as? NSDictionary)?["postedBy"] as? String {

Answer 1

尝试:-

  for child in snapshot.children{
            if let postedBy = child.value!["postedBy"] as? String { .. }}