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按照標題，我在處理socket.io時遇到了一些問題。它在第一個視圖控制器中連接得非常好，因此在第二個控制器中發生奇怪的事情。Swift中來自socket.io的意外古怪行爲
下面的代碼：
首先控制器：我宣佈兩個視圖控制器之間的連接目的，一些全局變量。
import UIKit
import SocketIOClientSwift
import SwiftyJSON
import CoreData
//declare some global variable
var patientCoreData = [NSManagedObject]()
var numberOfUsersExisting:Int = 0 //assign to 0 by default
var appUserData: Patient? //for specific user
var pSample: Array<Patient> = [] //for all user
//initiate socket globally
let socket = SocketIOClient(socketURL: "localhost:3000", options: [
"reconnects": true
])
func reportStatus(){
socket.on("connect") {data, ack in
print("Report status: View Controller connected")
socket.emit("click", "Client app connected")
}
}
func readDataFromSocket(completion: (data:AnyObject)->()){
socket.on("reply") {data, ack in
print("database replied")
completion(data: data)
}//socket
}//readDataFromSOCKET
func importData(){
reportStatus()
socket.connect()
readDataFromSocket(){ data in
let json = JSON(data)
let nou = json[0].count
if nou > 0 {
print("Test(1st VC): grabbing data from database")
for var i=0; i<nou; ++i{
numberOfUsersExisting = nou
pSample += [Patient(id: json[0][i]["ID"].intValue, name: json[0][i]["Name"].stringValue, gender: json[0][i]["Gender"].stringValue, mileage: json[0][i]["Mileage"].doubleValue)]
pSample.sortInPlace({$0.globalPatientMileAge < $1.globalPatientMileAge})
}
print("Successfully grabbed data")
}else{
print("No user in the database")
numberOfUsersExisting = 0
}
}//readDataFromSocket
}
class ViewController: UIViewController, UICollectionViewDataSource, UICollectionViewDelegate, UICollectionViewDelegateFlowLayout{
let prefs:NSUserDefaults = NSUserDefaults.standardUserDefaults()
}
override func viewDidLoad() {
super.viewDidLoad()
}
override func viewDidAppear(animated: Bool) {
super.viewDidAppear(animated)
print("First view appeared")
let prefs = NSUserDefaults.standardUserDefaults()
//if an user has logged in
let isLoggedIn = prefs.integerForKey("ISLOGGEDIN") as Int
if (isLoggedIn != 1){
print("No user currently, so heading to login screen")
socket.disconnect()
self.performSegueWithIdentifier("gotoLogin", sender: self)
}else{
print("ViewDidAppear: An user has been logged in")
let permissionToLoadData = prefs.integerForKey("ISLOGGEDIN")
if (permissionToLoadData != 1) {
print("Please grant permission to get data")
}else{
print("First view: connecting to database")
importData()
}//permission to load data
}
}//end of viewDidAppear
}
第二個控制器：
import UIKit
import SocketIOClientSwift
import SwiftyJSON
import CoreData
var nou:Int?
class LoginViewController: UIViewController {
let prefs:NSUserDefaults = NSUserDefaults.standardUserDefaults()
let registeredUserID = NSUserDefaults.standardUserDefaults().stringForKey("registerPatientID")
let appDel:AppDelegate = UIApplication.sharedApplication().delegate as! AppDelegate
func displayAlertMessage(userMessage:String){
let alert = UIAlertController(title: "Alert", message: userMessage, preferredStyle: UIAlertControllerStyle.Alert)
let okAction = UIAlertAction(title: "OK", style: UIAlertActionStyle.Default, handler: nil)
alert.addAction(okAction)
self.presentViewController(alert, animated: true, completion: nil)
}
func successMessage(userMessage:String){
let alert = UIAlertController(title: "Welcome Back", message: userMessage, preferredStyle: UIAlertControllerStyle.Alert)
let okAction = UIAlertAction(title: "OK", style: UIAlertActionStyle.Default, handler: nil)
alert.addAction(okAction)
self.presentViewController(alert, animated: true, completion: nil)
}
@IBOutlet weak var loginPatientID: UITextField!
@IBAction func LoginButton(sender: AnyObject) {
let logInUserID = loginPatientID.text
if (logInUserID!.isEmpty){
displayAlertMessage("Please enter your Patient ID!")
return
}else{
print("Test: requesting login permission from database")
socket.emit("loginRequest", logInUserID!)
print("Test: requested")
socket.on("loginReply") {data, ack in
let jsonLogin = JSON(data)
if jsonLogin[0].intValue == 1{
print("Test: ID Matched, putting up ViewController")
self.prefs.setObject(logInUserID, forKey: "AppUserID")
self.prefs.setInteger(1, forKey: "ISLOGGEDIN")
self.prefs.synchronize()
let permissionToLoadData = self.prefs.integerForKey("ISLOGGEDIN")
if (permissionToLoadData != 1) {
print("Please grant permission to get data")
}else{
print("First view: connecting to database")
importData()
print("Did you import?")
}//permission to load data
self.loginPatientID.resignFirstResponder()
self.dismissViewControllerAnimated(true, completion: nil)
}else if jsonLogin[0].intValue == 0{
self.displayAlertMessage("Sorry, you are not assigned to this program")
}else if jsonLogin[0].intValue == 3{
print("Test: Query problem")
}else{
print("Test: not getting anything from ID database")
}
}//socket.on
}//else
}//login button
override func viewDidLoad() {
super.viewDidLoad()
print("Login View Controller loaded")
}
override func viewDidAppear(animated: Bool) {
socket.connect()
print("LoginVC: establishing connection")
}
override func touchesBegan(touches: Set<UITouch>, withEvent event: UIEvent?) {
self.view.endEditing(true)
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
}
}
您可能已經注意到，在第一視圖控制器，當viewDidAppear（）如果用戶登錄時啓動，應用程序會檢查或不。如果有人已經登錄，那很好。如果沒有人登錄，它將執行一個循環（模式繼續）到秒視圖控制器。
登錄表單將顯示在第二個視圖控制器中，一旦用戶點擊登錄按鈕，你可能想看看代碼。
讓我們假設一切正常，直到涉及到importData（），該函數根本沒有啓動，但應用程序剛剛啓動，爲什麼？
下面是控制檯的屏幕截圖，請注意「您是否導入？」，如果啓動該功能，應用程序應從第一個視圖控制器返回一些附加消息。
