无法下标[String:AnyObject]类型的值?索引类型为String

问题描述：

我知道有很多相同的问题，但是仍然找不到解决我的错误的方法.请查看图片以获取更多详细信息.我使用了Xcode 7和Swift 2.0

I know have many the same question but still cannot find the way to fix my error. Please see the image for more detail. I used Xcode 7 and swift 2.0

编辑:对Swift的警告进行了修正. finnaly (change?[NSKeyValueChangeNewKey]?.boolValue)!修复了错误

fcking the warning of Swift. finnaly (change?[NSKeyValueChangeNewKey]?.boolValue)! fixed the error

答

change是可选的.要么打开可选的

change is an optional. Either unwrap the optional

let isCaptureStillImage = change![NSKeyValueChangeNewKey]!.boolValue

或使用可选的绑定

if let changeNewKey = change?[NSKeyValueChangeNewKey] {
  let isCaptureStillImage = changeNewKey.boolValue

...