【发布时间】：2016-02-09 19:44:17
【问题描述】：
对 Swift 来说相当陌生。尝试执行简单的 REST API 提取。我在代码中没有收到任何错误，但是当我在调试模式下查看代码时 session.DataTaskWithRequest 似乎没有执行。
<code>
class ViewController: UIViewController {
override func viewDidLoad() {
super.viewDidLoad()
let requestURL: NSURL = NSURL(string: "http://www.learnswiftonline.com/Samples/subway.json")!
let urlRequest: NSMutableURLRequest = NSMutableURLRequest(URL: requestURL)
let session = NSURLSession.sharedSession()
let task = session.dataTaskWithRequest(urlRequest, completionHandler: {(data, response, error) -> Void in
guard let responseData = data else {
print("Error: did not receive data")
return
}
guard error == nil else {
print("error calling GET on /posts/1")
print(error)
return
}
let httpResponse = response as! NSHTTPURLResponse
let statusCode = httpResponse.statusCode
if (statusCode == 200) {
print("Everyone is fine, file downloaded successfully.")
}
})
task.resume()
// Do any additional setup after loading the view, typically from a nib.
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
}
</code>
我可以毫无问题地在浏览器中点击 url，我什至尝试过其他测试 url。
有什么想法吗？
【问题讨论】：