Command Failed Due To Signal Fault - Swift 2.2 Xcode 7.3

问题

I am in the process of updating all my swift syntax after updating to xcode 7.3 In the process, I got some errors about ambiguous use of subscript swift and I believe that this error is also causing the Signal Fault.

The code in question:

 override func tableView(tableView: UITableView, didSelectRowAtIndexPath indexPath: NSIndexPath) {
    var arry:NSArray = Array(self.participants)
         arry = arry.sort {
         item1, item2 in
         // ambiguous use of subscript swift error for both these lines
         let date1 = item1["fullName"] as String
         let date2 = item2["fullName"] as String
         return date1 > date2
    }

Edit

Declaration of participants comes from another controller here:

        func gotoMembers(){

        let set:NSSet = self.conversation.participants
        let arr = set.allObjects //Swift Array
        UserManager.sharedManager.queryForAllUsersWithCompletion(arr as! [String], completion:{ (users: NSArray?, error: NSError?) in
            if error == nil {
               //participants declared here and passed into the participant controller
                let participants = NSSet(array: users as! [PFUser]) as Set<NSObject>
                let controller = ParticipantTableViewController(participants: participants, sortType: ATLParticipantPickerSortType.FirstName)
                controller.delegate = self
                self.navigationController?.pushViewController(controller, animated:true);
            } else {
                appDelegate.log.error("Error querying for All Users: \(error)")
            }
        })

    }

Update

回答1:

First of all use Swift native types a much as possible, for example the type of the contents of an NSArray object is unspecified.

Second of all use type annotations as few as possible, in the case

var array = Array(self.participants)

without an annotation you get a Swift Array for free and the compiler knows the type of the contents which is PFUser. The function sortInPlace() sorts the array itself without a return value and you have to forced downcast the fullName values to String

     array.sortInPlace {
        user1, user2 in

        let date1 = user1["fullName"] as! String
        let date2 = user2["fullName"] as! String
        return date1 > date2
}

and use the proper type Set<PFUser> rather then Set<NSObject> and probably users: [PFUser]? in the completion handler rather then users: NSArray?

Edit: The beginning of the queryForAllUsersWithCompletion method is supposed to look like

UserManager.sharedManager.queryForAllUsersWithCompletion(arr as! [String], completion:{ (users: [PFUser]?, error: NSError?) in
    if error == nil {
       //participants declared here and passed into the participant controller
       let participants = Set<PFUser>(array: users!)

来源：https://stackoverflow.com/questions/36258298/command-failed-due-to-signal-fault-swift-2-2-xcode-7-3

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ios

xcode

swift2

xcode7.3