ios - Swift 2.0 API 调用

Question

我用 swift 编写了一个 iOS 应用程序，必须将其转换为 2.0 才能将其发布到应用程序商店。该应用程序之前运行良好，但在调用 JSON API 时遇到了一些迁移问题。我添加了一个 catch 语句，但我仍然不断出错。现在它说我在最后缺少一个表达式，没有什么描述性的。任何帮助将不胜感激。

这是我的代码:

let url : String = "http://xproshowcasex.api.channel.livestream.com/2.0/livestatus.json"
    let request : NSMutableURLRequest = NSMutableURLRequest()
    request.URL = NSURL(string: url)
    request.HTTPMethod = "GET"

    NSURLSession.sendAsynchronousRequest(request, queue: NSOperationQueue(), completionHandler:{ (response:NSURLResponse?, data: NSData?, error: NSError?) -> Void in

        let jsonResult: AnyObject?
        do {
            jsonResult = try NSJSONSerialization.JSONObjectWithData(data!, options: [])
            print(jsonResult, terminator: "");
            let channel: NSDictionary! = jsonResult!.valueForKey("channel") as! NSDictionary;
            print(channel, terminator: "");
            let result: NSNumber! = channel.valueForKey("isLive") as! NSNumber;
            print(result, terminator: "");

            if (result == 0)
            {
                let alertController = UIAlertController(title: "", message:
                    "There is no live stream right now", preferredStyle: UIAlertControllerStyle.Alert)
                alertController.addAction(UIAlertAction(title: "Dismiss", style: UIAlertActionStyle.Default,handler: nil))

                self.presentViewController(alertController, animated: true, completion: nil)
            }

        }
         catch
         {
            // TODO: handle
        }
        )
    }
}

Answer 1

我不知道sendAsynchronousRequest是在哪里为NSURLSession定义的，所以我无法检查方法签名来确保你正确使用它，但是开始你在最后的错误位置有一个括号。

就其值(value)而言，在未来，这种“预期表达式”错误是一种语法错误，它指向您没有按照编译器预期的方式键入的内容。在这些情况下，仔细检查大括号和圆括号以及其他常见的语法混淆区域。

let url : String = "http://xproshowcasex.api.channel.livestream.com/2.0/livestatus.json"
let request : NSMutableURLRequest = NSMutableURLRequest()
request.URL = NSURL(string: url)
request.HTTPMethod = "GET"


NSURLSession.sendAsynchronousRequest(request, queue: NSOperationQueue(), completionHandler:{ (response:NSURLResponse?, data: NSData?, error: NSError?) -> Void in

    let jsonResult: AnyObject?
    do {
        jsonResult = try NSJSONSerialization.JSONObjectWithData(data!, options: [])
        print(jsonResult, terminator: "");
        let channel: NSDictionary! = jsonResult!.valueForKey("channel") as! NSDictionary;
        print(channel, terminator: "");
        let result: NSNumber! = channel.valueForKey("isLive") as! NSNumber;
        print(result, terminator: "");

        if (result == 0)
        {
            let alertController = UIAlertController(title: "", message: "There is no live stream right now", preferredStyle: UIAlertControllerStyle.Alert)
            alertController.addAction(UIAlertAction(title: "Dismiss", style: UIAlertActionStyle.Default,handler: nil))

            self.presentViewController(alertController, animated: true, completion: nil)
        }

    }
    catch
    {
        // TODO: handle
    }
})