解析和Swift 1.2问题

Question

这段代码在Swift 1.1中运行良好…只是试图找出1.2中所做的更改以使其不兼容：

@IBAction func load_click(sender: AnyObject) {

    var query = PFQuery(className: "myClass")
    query.getObjectInBackgroundWithId("MPSVivtvJR", block: { (object:PFObject!, error: NSError) -> Void in

        let theName = object["name"] as String
        let theAge = object["age"] as Int?

        println(theName)
        println(theAge)

    })
}

它给了我错误： 无法使用类型为’（String，block：（PFObject !, NSError）- >
Void）的参数列表调用’GetObjectInBackgroundWithId’

有任何想法吗？谢谢！

Answer 1

现在，使用Swift 1.2时，您应该更加谨慎地展开可选项。因此，在具有PFObject和的闭包中NSError，删除感叹号或添加问号使其成为可选。

然后，更安全地解开对象。尝试如下：

// You can create this in a separate file where you save your models

struct myUser {
    let name: String?
    let age: Int?
}

// Now this in the view controller

@IBAction func load_click(sender: AnyObject) {
    var query = PFQuery(className: "myClass")
    query.getObjectInBackgroundWithId("MPSVivtvJR", block: {
        (object:PFObject!, error: NSError?) -> Void in

        if let thisName = object["name"] as? String{
            if let thisAge = object["age"] as? Int{
                let user = myUser(name: thisName, age: thisAge)
                println(user)
            }
        }

    })
}