如何在swift 3中从NSNotification获取userinfo

Question

我在swift3中遇到了这个错误:

Cannot convert value of type [AnyHashable : Any] to type NSDictionary in coercion.

我的代码是:

  func downloadProgress(notification:NSNotification){

    if let userInfo = notification.userInfo as NSDictionary
    {
         print(userInfo) // [AnyHashable("progressPercentage"): 0.82530790852915281]

      if let progressValue = userInfo["progressPercentage"] as? Float {
        if progressValue > 0.01{

        }
      }
    }
  }

实际的userInfo值是["progressPercentage": 0.82530790852915281]打印出来但[AnyHashable("progressPercentage"): 0.82530790852915281]不满足if条件.

编辑:

没有运气notification.userInfo as? [AnyHashable: Any],但现在适合notification.userInfo as? [String: AnyObject]和notification.userInfo as? [String: Any]

Answer 1

键入转换

使用

 func downloadProgress(notification:NSNotification){

if let userInfo = notification.userInfo as [String: Any] // or use if you know the type  [AnyHashable : Any]
{
     print(userInfo) 

  if let progressValue = userInfo["progressPercentage"] as? Float {
    if progressValue > 0.01{

    }
  }
}
 }

有关更多信息,请参阅此API参考文档