ios - Swift:以编程方式导航到 ViewController 并传递数据

Question

我最近开始学习swift，到目前为止效果还不错。目前我在尝试在 View Controller 之间传递数据时遇到问题。我设法弄清楚如何使用导航 Controller 以编程方式在两个 View Controller 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 View 。

这是我目前的尝试。非常感谢任何帮助!

View Controller :

/* 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 View Controller :

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.
}
}

Answer 1

prepareForSegue 方法在您的应用程序的 Storyboard 执行转场(您在 Storyboard 中使用 Interface Builder 创建的连接)时调用。在上面的代码中，尽管您自己使用 presentViewController 呈现 Controller 。在这种情况下，不会触发 prepareForSegue。您可以在展示 Controller 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