swift - 解析和 Swift 问题查询

Question

这是我的错误信息:

Cannot invoke 'getObjectInBackgroundWithId' with an argument list of type '(String, (PFObject!,NSError!) -> Void)'

我的代码是这样的:

    func CallData(){

    var query : PFQuery = PFQuery(className: "QuestionsandAnswers")
    query.getObjectInBackgroundWithId("iXCrgCLKk2"){
        (Object : PFObject!, error : NSError!) -> Void in
        if (error == nil){
            self.Question = Object["Question"] as String!
            self.Answers = Object["Answers"] as Array!
            self.Answer = Object["Answer"] as String!

            if (self.Answers.count > 0){
                self.QuestionLabel.text = self.Question
            }
        } else {
            NSLog("There is something wrong!")
        }
    }
}

我试过更改 PFObject 和 NSError 后面的感叹号/问号/什么都没有，但没有任何效果。但是，如果我在 PFObject 和 NSError 后面都加上问号，我会收到一条新的错误消息:

'AnyObject' is not convertible to 'String!';did you mean to use 'as!' to force downcast?

如果我将代码更改为 as!，则会出现此错误:

Cannot assign immutable value of type 'String!'

关于如何解决这个问题的任何想法？感谢您的帮助!

Answer 1

看看: http://blog.parse.com/announcements/building-apps-with-parse-and-swift/

我觉得这行得通

var query = PFQuery(className: "QuestionsandAnswers")
    query.getObjectInBackgroundWithId("iXCrgCLKk2", block: { (object:PFObject?, error:NSError?) -> Void in
        if let error = error {
            //error
        } else if let object = object{
            //do something with your object as PFObject
            // such as
            var Question:String = object.objectForKey("Question") as! String

        }
    })