UILabel data to UIAlert issue in xcode 8, error - swift3

Question

I made an alert and I tried to follow a tutorial and put it into my code. I put the code in a few different places but the errors just kept getting worse. I finally just put it at the bottom, because thats where I ended up getting the fewest errors. I'm new to xcode so this very basic thing is very hard for me. Furthermore, I get errors all over the place when I put this in, and I have no idea how to fix this. Moreover, what I am trying to do is take the data that is being saved in my UILabel which is a name, and I want that to be shown up in the clickable part of the alert that "dismisses" the alert, but I have no idea how to do that or even get started when I can't add a basic alert into my code. Any help would be great source code even better. Sorry for all the questions. Thanks again in advance.
import UIKit
import MultipeerConnectivity
class ViewController: UIViewController, MCBrowserViewControllerDelegate {
#IBOutlet weak var input: UITextField!
#IBOutlet weak var output: UILabel!
#IBAction func action(_ sender: Any) {
output.text = input.text
UserDefaults.standard.set(input.text, forKey: "MyName")
input.text = ""
}
var currentPlayer:String!
var appDelegate:AppDelegate!
override func viewDidLoad() {
super.viewDidLoad()
appDelegate = UIApplication.shared.delegate as! AppDelegate
appDelegate.MPCHandler.setupPeerWithDisplayName(UIDevice.current.name)
appDelegate.MPCHandler.setupSession()
appDelegate.MPCHandler.advertiseSelf(true)
NotificationCenter.default.addObserver(self, selector: Selector(("peerChangedStateWithNotification:")), name: NSNotification.Name(rawValue: "MPC_DidChangeStateNotification"), object: nil)
NotificationCenter.default.addObserver(self, selector: Selector(("handleReceivedDataWithNotification:")), name: NSNotification.Name(rawValue: "MPC_DidReceiveDataNotification"), object: nil)
}
#IBAction func connect(_ sender: Any) {
if appDelegate.MPCHandler.session != nil{
appDelegate.MPCHandler.setupBrowser()
appDelegate.MPCHandler.browser.delegate = self
self.present(appDelegate.MPCHandler.browser, animated: true, completion: nil)
}
}
func peerChangedStateWithNotification(notification:NSNotification){
let userInfo = NSDictionary(dictionary: notification.userInfo!)
let state = userInfo.object(forKey: "state") as! Int
if state != MCSessionState.connecting.rawValue{
self.navigationItem.title = "Connected"
}
}
func browserViewControllerDidFinish(_ browserViewController: MCBrowserViewController) {
appDelegate.MPCHandler.browser.dismiss(animated: true, completion: nil)
}
func browserViewControllerWasCancelled(_ browserViewController: MCBrowserViewController) {
appDelegate.MPCHandler.browser.dismiss(animated: true, completion: nil)
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
override func viewDidAppear(_ animated: Bool) {
if let x = UserDefaults.standard.object(forKey:"myName") as?
String
{
output.text = x
}
}
}
func viewDidAppear(_animated: Bool) {
createAlert(title: "HI", message: "ARE YOU READY")
}
func createAlert (title: String, message:String)
{
let alert = UIAlertController(title: title, message: message, preferredStyle: UIAlertControllerStyle.alert)
alert.addAction(UIAlertAction(title: "HI", style: UIAlertActionStyle.default, handler: { (action) in alert.dismiss(animated: true, completion: nil);))
self.present(alert,animated: true, completion:nil)
}
}

Answer 1

The error you are most probably getting is Invalid redeclaration of 'viewDidAppear' means you are trying to add viewDidAppear method twice in your ViewController. So remove the below one method form your code and call createAlert inside the already exist viewDidAppear one.
Your second mistake is you forgot to add } for UIAlertActionHandler and there is no need to call dismiss on alert action it will automatically dismiss the alert.
You need to also change your selector syntax to Swift3 one and also you forgot to add handleReceivedDataWithNotification with your code.
Now with Swift use Swift native dictionary type instead of NSDictionary, so change your controller with below one to get your desired output.
class ViewController: UIViewController, MCBrowserViewControllerDelegate {
#IBOutlet weak var input: UITextField!
#IBOutlet weak var output: UILabel!
var currentPlayer:String!
var appDelegate:AppDelegate!
override func viewDidLoad() {
super.viewDidLoad()
appDelegate = UIApplication.shared.delegate as! AppDelegate
appDelegate.MPCHandler.setupPeerWithDisplayName(UIDevice.current.name)
appDelegate.MPCHandler.setupSession()
appDelegate.MPCHandler.advertiseSelf(true)
NotificationCenter.default.addObserver(self, selector: #selector(peerChangedStateWithNotification(_:)), name: NSNotification.Name(rawValue: "MPC_DidChangeStateNotification"), object: nil)
NotificationCenter.default.addObserver(self, selector: #selector(handleReceivedDataWithNotification(_:)), name: NSNotification.Name(rawValue: "MPC_DidReceiveDataNotification"), object: nil)
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
#IBAction func connect(_ sender: Any) {
if appDelegate.MPCHandler.session != nil{
appDelegate.MPCHandler.setupBrowser()
appDelegate.MPCHandler.browser.delegate = self
self.present(appDelegate.MPCHandler.browser, animated: true, completion: nil)
}
}
#IBAction func action(_ sender: Any) {
output.text = input.text
UserDefaults.standard.set(input.text, forKey: "MyName")
input.text = ""
}
func peerChangedStateWithNotification(_ notification: Notification) {
let userInfo = notification.userInfo!
let state = userInfo["state"] as! Int
if state != MCSessionState.connecting.rawValue{
self.navigationItem.title = "Connected"
}
}
func handleReceivedDataWithNotification(_ notification: Notification) {
let userInfo = notification.userInfo!
print(userInfo)
}
func browserViewControllerDidFinish(_ browserViewController: MCBrowserViewController) {
appDelegate.MPCHandler.browser.dismiss(animated: true, completion: nil)
}
func browserViewControllerWasCancelled(_ browserViewController: MCBrowserViewController) {
appDelegate.MPCHandler.browser.dismiss(animated: true, completion: nil)
}
override func viewDidAppear(_ animated: Bool) {
if let x = UserDefaults.standard.string(forKey: "myName") {
output.text = x
}
else {
output.text = "Default Name" //Set here default Name
}
self.createAlert(title: "HI", message: "ARE YOU READY")
}
func createAlert (title: String, message:String)
{
let alert = UIAlertController(title: title, message: message, preferredStyle: UIAlertControllerStyle.alert)
alert.addAction(UIAlertAction(title: output.text, style: UIAlertActionStyle.default, handler: { (action) in
}))
self.present(alert,animated: true, completion:nil)
}
}

Answer 2

import UIKit
import MultipeerConnectivity
class ViewController: UIViewController, MCBrowserViewControllerDelegate {
#IBOutlet weak var input: UITextField!
#IBOutlet weak var output: UILabel!
#IBAction func dick(_ sender: Any) {
output.text = input.text
UserDefaults.standard.set(input.text, forKey: "MyName")
input.text = ""
}
var currentPlayer:String!
var appDelegate:AppDelegate!
override func viewDidLoad() {
super.viewDidLoad()
appDelegate = UIApplication.shared.delegate as! AppDelegate
appDelegate.MPCHandler.setupPeerWithDisplayName(UIDevice.current.name)
appDelegate.MPCHandler.setupSession()
appDelegate.MPCHandler.advertiseSelf(true)
NotificationCenter.default.addObserver(self, selector: #selector(ViewController.peerChangedStateWithNotification(_:)), name: NSNotification.Name(rawValue: "MPC_DidChangeStateNotification"), object: nil)
NotificationCenter.default.addObserver(self, selector: #selector(ViewController.handleReceivedDataWithNotification(_:)), name: NSNotification.Name(rawValue: "MPC_DidReceiveDataNotification"), object: nil)
}
#IBAction func connect(_ sender: Any) {
if appDelegate.MPCHandler.session != nil{
appDelegate.MPCHandler.setupBrowser()
appDelegate.MPCHandler.browser.delegate = self
self.present(appDelegate.MPCHandler.browser, animated: true, completion: nil)
}
}
#IBAction func action(_ sender: Any) {
output.text = input.text
UserDefaults.standard.set(input.text, forKey: "MyName")
input.text = ""
}
func peerChangedStateWithNotification(_ notification: Notification) {
let userInfo = notification.userInfo!
let state = userInfo["state"] as! Int
if state != MCSessionState.connecting.rawValue{
self.navigationItem.title = "Connected"
}
}
func handleReceivedDataWithNotification(_ notification: Notification) {
let userInfo = notification.userInfo!
print(userInfo)
}
func browserViewControllerDidFinish(_ browserViewController: MCBrowserViewController) {
appDelegate.MPCHandler.browser.dismiss(animated: true, completion: nil)
}
func browserViewControllerWasCancelled(_ browserViewController: MCBrowserViewController) {
appDelegate.MPCHandler.browser.dismiss(animated: true, completion: nil)
}
*func viewdidloadOverride; func viewDidAppear*(_ animated: Bool) {
if let x = UserDefaults.standard.string(forKey: "myName") {
output.text = x
}
else {
output.text = "x" //Set here default Name
}
self.createAlert(title: "HI", message: "ARE YOU READY")
}
func createAlert (title: String, message:String)
{
let alert = UIAlertController(title: title, message: message, preferredStyle: UIAlertControllerStyle.alert)
alert.addAction(UIAlertAction(title: output.text, style: UIAlertActionStyle.default, handler: { (action) in
}))
self.present(alert,animated: true, completion:nil)
}
}