ios - 重新单击按钮后程序不会更新

Question

我的程序运行良好，除了如果我重新单击“Enter”按钮，它不会第二次更新。它在我第一次点击它时有效，但在第二次点击时无效。

代码如下:

import UIKit

class ViewController: UIViewController, NSURLConnectionDelegate {

lazy var data = NSMutableData()

@IBOutlet weak var searchField: UITextField!

@IBOutlet weak var name: UILabel!

@IBOutlet weak var summonerLevel: UILabel!

@IBOutlet weak var profileIconId: UILabel!

@IBAction func enterButton(sender: AnyObject) {

    startConnection()

}

override func viewDidLoad() {
    super.viewDidLoad()
    // Do any additional setup after loading the view, typically from a nib.
}

override func viewWillAppear(animated: Bool) {
    super.viewWillAppear(animated)

}

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

func startConnection(){
    println("start connection began")
    let urlPath: String = "https://na.api.pvp.net/api/lol/na/v1.4/summoner/by-name/" + searchField.text + "?api_key=dd5bf142-df4a-4eed-be7f-8f6f908dcfe6"
    var url: NSURL = NSURL(string: urlPath)!
    var request: NSURLRequest = NSURLRequest(URL: url)
    var connection: NSURLConnection = NSURLConnection(request: request, delegate: self, startImmediately: false)!
    connection.start()
}

func connection(connection: NSURLConnection!, didReceiveData data: NSData!){
    self.data.appendData(data)
}

func buttonAction(sender: UIButton!){
    startConnection()
}

func connectionDidFinishLoading(connection: NSURLConnection) {

    var err: NSError?

    if let jsonResult = NSJSONSerialization.JSONObjectWithData(data, options: NSJSONReadingOptions.MutableContainers, error: &err) as? NSDictionary,
        let include = jsonResult.objectForKey(searchField.text) as? NSDictionary {
            //where the program stops running after I click enter the second time (it doesn't literally 'stop' running, it just doesn't execute the rest of this code, keep in mind its the second time I click enter with a new username in the textfield value)
            if let name1 = include[ "name" ] as? String {
                name.text = name1
                println(name1)
            }

            if let summLevel = include[ "summonerLevel" ] as? NSNumber {
                summonerLevel.text = "\(summLevel.integerValue)"
                println(summLevel)

            }
            if let profIconId = include[ "profileIconId" ] as? NSNumber {
                profileIconId.text = "\(profIconId.integerValue)"
                println(profIconId)
            }
    }
}

这是我正在解析的内容(我认为它没有任何用处，但以防万一):

{"soon2challenger":{"id":43993167,"name":"soon2challenger","profileIconId":844,"summonerLevel":30,"revisionDate":1435549418000}}

我想让程序做的是，当我为文本字段输入不同的值并单击“Enter”时，我希望它用新信息更新。我曾尝试将 let 值更改为 vars，但这似乎无法正常工作。

这是我第一次输入值并在 iOS 模拟器中单击“Enter”时的样子:

这是我第二次输入新值并单击“Enter”时的样子，实际上没有任何变化/发生:

Answer 1

我认为有两个问题:

一个问题是你可以在按钮完成前点击两次

另一个是你一直在积累变量数据而不是清空

我在代码中添加了一些可能有帮助的注释。

import UIKit
class ViewController: UIViewController, NSURLConnectionDelegate {
lazy var data = NSMutableData()
@IBOutlet weak var searchField: UITextField!
@IBOutlet weak var name: UILabel!
@IBOutlet weak var summonerLevel: UILabel!
@IBOutlet weak var profileIconId: UILabel!
//Create a new outlet to the Button
@IBOutlet weak var enterButton: UIButton!

@IBAction func enterButton(sender: AnyObject) {
    //disable the button until the request finishes
    enterButton.enable = false
    //Clear the old data from data
    data.setData(NSData())
    startConnection()
}

func startConnection(){
    println("start connection began")
    let urlPath: String = "https://na.api.pvp.net/api/lol/na/v1.4/summoner/by-name/" + searchField.text + "?api_key=dd5bf142-df4a-4eed-be7f-8f6f908dcfe6"
    var url: NSURL = NSURL(string: urlPath)!
    var request: NSURLRequest = NSURLRequest(URL: url)
    var connection: NSURLConnection = NSURLConnection(request: request, delegate: self, startImmediately: false)!
    connection.start()
}

func connection(connection: NSURLConnection!, didReceiveData data: NSData!){
    self.data.appendData(data)
}

//You don't need this you already have an outlet
func buttonAction(sender: UIButton!){
    startConnection()
}

func connectionDidFinishLoading(connection: NSURLConnection) {

    var err: NSError?

    if let jsonResult = NSJSONSerialization.JSONObjectWithData(data, options: NSJSONReadingOptions.MutableContainers, error: &err) as? NSDictionary,
        let include = jsonResult.objectForKey(searchField.text) as? NSDictionary {
            //where the program stops running after I click enter the second time (it doesn't literally 'stop' running, it just doesn't execute the rest of this code, keep in mind its the second time I click enter with a new username in the textfield value)
            if let name1 = include[ "name" ] as? String {
                name.text = name1
                println(name1)
            }

            if let summLevel = include[ "summonerLevel" ] as? NSNumber {
                summonerLevel.text = "\(summLevel.integerValue)"
                println(summLevel)

            }
            if let profIconId = include[ "profileIconId" ] as? NSNumber {
                profileIconId.text = "\(profIconId.integerValue)"
                println(profIconId)
            }
            //re-enable the button for new requests 
            enterButton.enable = true
    }
}