Swift：以编程方式导航到 ViewController 并传递数据

我最近开始学习swift，到目前为止还不错。目前，我在尝试在视图控制器之间传递数据时遇到问题。我设法弄清楚如何使用导航控制器以编程方式在两个视图控制器之间导航。唯一的问题是现在我很难弄清楚如何将用户输入的三个字符串（对于 json api）传递到下一个视图。

这是我目前的尝试。任何帮助深表感谢！

视图控制器：

/* Get the status code of the connection attempt */
func connection(connection:NSURLConnection, didReceiveResponse response: NSURLResponse){

    let status = (response as! NSHTTPURLResponse).statusCode
    //println("status code is \(status)")

    if(status == 200){

        var next = self.storyboard?.instantiateViewControllerWithIdentifier("SecondViewController") as! SecondViewController
        self.presentViewController(next, animated: false, completion: nil)
    }
    else{

        RKDropdownAlert.title("Error", message:"Please enter valid credentials.", backgroundColor:UIColor.redColor(), textColor:UIColor.whiteColor(), time:3)
        drawErrorBorder(usernameField);
        usernameField.text = "";
        drawErrorBorder(passwordField);
        passwordField.text = "";
    }
}

override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject!) {

    let navigationController = segue.destinationViewController as! UINavigationController
    let newProjectVC = navigationController.topViewController as! SecondViewController
    newProjectVC.ip = ipAddressField.text
    newProjectVC.username = usernameField.text
    newProjectVC.password = passwordField.text
}

第二个视图控制器：

import UIKit

class SecondViewController: UIViewController {

var ip:NSString!
var username:NSString!
var password:NSString!

override func viewDidLoad() {
    super.viewDidLoad()

    println("\(ip):\(username):\(password)")
}

override func didReceiveMemoryWarning() {
    super.didReceiveMemoryWarning()
    // Dispose of any resources that can be recreated.
}
}

方法prepareForSegue当应用程序的故事板执行 segue（您使用 Interface Builder 在故事板中创建的连接）时调用。在上面的代码中，尽管您自己呈现控制器presentViewController。在这种情况下，prepareForSegue没有被解雇。您可以在展示控制器之前进行设置：

let next = self.storyboard?.instantiateViewControllerWithIdentifier("SecondViewController") as! SecondViewController
next.ip = ipAddressField.text
next.username = usernameField.text
next.password = passwordField.text
self.presentViewController(next, animated: false, completion: nil)

您可以阅读有关 segue 的更多信息here https://developer.apple.com/library/ios/recipes/xcode_help-IB_storyboard/chapters/StoryboardSegue.html