Question

好的，我是新手，并且正在慢慢地完成开发课程。但是我意识到如果我能够解决这个问题，那将是一个很长的前进道路。

我在服务器上调用PHP文件并返回JSON数据。这有效。我可以打印变量

print("firstNameValue: \(firstNameValue)")

我现在想要将一个变量... firstNameValue的值输出到名为textField的文本字段中。

我是Swift的新手，我在思考＆＃34;全局变量？＆＃34;。这有效，但我想等待HTTP调用的响应完成然后更新文本字段。

我希望你能提供帮助。我是OOP的新手，我的头脑也在爆裂。

import UIKit 

class ViewController: UIViewController {

    @IBOutlet weak var feel: UITextField!

    @IBAction func anxious(sender: AnyObject) {



        let myUrl = NSURL(string: "http://mywebsite.com/Jamesbond.php");

        let request = NSMutableURLRequest(URL:myUrl!);

        request.HTTPMethod = "POST";// Compose a query string

        let postString = "firstName=James&lastName=Bond";

        request.HTTPBody = postString.dataUsingEncoding(NSUTF8StringEncoding);

        let task = NSURLSession.sharedSession().dataTaskWithRequest(request) {
            data, response, error in

            if error != nil
            {
                print("error=\(error)")
                return
            }

            // You can print out response object
            print("response = \(response)")

            // Print out response body
            let responseString = NSString(data: data!, encoding: NSUTF8StringEncoding)
            print("responseString = \(responseString)")

            //Let's convert response sent from a server side script to a NSDictionary object:
            do {
                let myJSON =  try NSJSONSerialization.JSONObjectWithData(data!, options: .MutableContainers) as? NSDictionary

                if let parseJSON = myJSON {

                    // Now we can access value of First Name by its key
                    let firstNameValue = parseJSON["firstName"] as? String

                    print("firstNameValue: \(firstNameValue)")

                  EDIT::the below two lines solved it.
                    dispatch_async(dispatch_get_main_queue()) {
                    self.textField.text = firstNameValue}


                }
            } catch {
                print(error)
            }
        }
        task.resume()

    }
    @IBOutlet weak var textField: UITextField!




    @IBAction func submit(sender: AnyObject) {
        print("hello")
        let a = 9
        let b = 10
        let c = (a*b)
        textField.text="You are a banana \(c)"

    }




    override func viewDidLoad() {
        super.viewDidLoad()
        // 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.
    }

Answer 1

必须在完成处理程序中更新文本字段，因为dataTaskWithRequest异步工作。

此代码执行所有必需的可选绑定检查，并运行该行以更新主线程上的文本字段。

...     
do {
   if let myJSON =  try NSJSONSerialization.JSONObjectWithData(data!, options: []) as? [String:AnyObject],
      firstNameValue = parseJSON["firstName"] as? String {
         print("firstNameValue: \(firstNameValue)")

         dispatch_async(dispatch_get_main_queue()) {
           self.textField.text = firstNameValue
         }
   }
}
catch {
    print(error)
}

在这种情况下根本不需要选项.MutableContainers。

将IBAction中的变量值传递给IBOutlet

1 个答案: