Question

升级到Xcode 8（Swift 3）后，当我尝试单步执行快照中的子记录时，我的Firebase查询出现错误NSFastEnumerationIterator.Element (aka Any) does not conform to protocol 'AnyObject'：

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"]，这会引发错误。然后我尝试将其更改为

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

但是它会抛出不同的错误Binary operator != cannot be applied to operands of type _ and _

我是朝着正确的方向前进的吗？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 { .. }}