Swift: Receive UDP with GCDAsyncUdpSocket - ios

Question

BACKGROUND:
I want to be able to send and receive UDP packets between my iOS app and a server.
The server echoes back every incoming message to the client the app. The server is tested and confirmed working. I have a StartViewController which starting up two classes that implements GCDAsyncUdpSocketDelegate, one for sending and one for receiving. The "sending socket" is working, the server receives the messages.
PROBLEM:
The app never get the incoming message back after it been sent. Something with the listening socket setup is probably wrong since didReceiveData never get called.
Have I done this completely wrong?
Start:
class StartViewController: UIViewController {
var inSocket : InSocket!
var outSocket : OutSocket!
override func viewDidLoad() {
super.viewDidLoad()
inSocket = InSocket()
outSocket = OutSocket()
}
#IBAction func goButton(sender: UIButton) {
outSocket.send("This is a message!")
}
}
Receive:
class InSocket: NSObject, GCDAsyncUdpSocketDelegate {
let IP = "255.255.255.255"
let PORT:UInt16 = 5556
var socket:GCDAsyncUdpSocket!
override init(){
super.init()
setupConnection()
}
func setupConnection(){
var error : NSError?
socket = GCDAsyncUdpSocket(delegate: self, delegateQueue: dispatch_get_main_queue())
socket.bindToPort(PORT, error: &error)
socket.enableBroadcast(true, error: &error)
socket.joinMulticastGroup(IP, error: &error)
socket.beginReceiving(&error)
}
func udpSocket(sock: GCDAsyncUdpSocket!, didReceiveData data: NSData!, fromAddress address: NSData!, withFilterContext filterContext: AnyObject!) {
println("incoming message: \(data)");
}
}
Send:
class OutSocket: NSObject, GCDAsyncUdpSocketDelegate {
let IP = "90.112.76.180"
let PORT:UInt16 = 5556
var socket:GCDAsyncUdpSocket!
override init(){
super.init()
setupConnection()
}
func setupConnection(){
var error : NSError?
socket = GCDAsyncUdpSocket(delegate: self, delegateQueue: dispatch_get_main_queue())
socket.connectToHost(IP, onPort: PORT, error: &error)
}
func send(message:String){
let data = message.dataUsingEncoding(NSUTF8StringEncoding)
socket.sendData(data, withTimeout: 2, tag: 0)
}
func udpSocket(sock: GCDAsyncUdpSocket!, didConnectToAddress address: NSData!) {
println("didConnectToAddress");
}
func udpSocket(sock: GCDAsyncUdpSocket!, didNotConnect error: NSError!) {
println("didNotConnect \(error)")
}
func udpSocket(sock: GCDAsyncUdpSocket!, didSendDataWithTag tag: Int) {
println("didSendDataWithTag")
}
func udpSocket(sock: GCDAsyncUdpSocket!, didNotSendDataWithTag tag: Int, dueToError error: NSError!) {
println("didNotSendDataWithTag")
}
}
Edit:
Added forgotten code line.

Answer 1

I finally got it to work with this socket setup:
func setupConnection(){
var error : NSError?
socket = GCDAsyncUdpSocket(delegate: self, delegateQueue: dispatch_get_main_queue())
socket.bindToPort(PORT, error: &error)
socket.connectToHost(SERVER_IP, onPort: PORT, error: &error)
socket.beginReceiving(&error)
send("ping")
}
func send(message:String){
let data = message.dataUsingEncoding(NSUTF8StringEncoding)
socket.sendData(data, withTimeout: 2, tag: 0)
}

Answer 2

Apple Swift version 4.2.1 Well Tested UDP Example:-
STEP 1 :- pod 'CocoaAsyncSocket'
STEP 2 :- import CocoaAsyncSocket in your UIViewController.
STEP 3 :- UIViewController
import UIKit
import CocoaAsyncSocket
class ViewController: UIViewController {
#IBOutlet weak var btnOnOff: LightButton!
#IBOutlet weak var lblStatus: UILabel!
var inSocket : InSocket!
var outSocket : OutSocket!
override func viewDidLoad() {
super.viewDidLoad()
lblStatus.isHidden = true
inSocket = InSocket()
outSocket = OutSocket()
outSocket.setupConnection {
self.lblStatus.isHidden = false
}
}
#IBAction func btnLight(_ sender: Any) {
let signal:Signal = Signal()
self.outSocket.send(signal: signal)
}
}
STEP 4 :- Reciving Socket
//Reciving End...
class InSocket: NSObject, GCDAsyncUdpSocketDelegate {
//let IP = "10.123.45.2"
let IP = "127.0.0.1"
let PORT:UInt16 = 5001
var socket:GCDAsyncUdpSocket!
override init(){
super.init()
setupConnection()
}
func setupConnection(){
socket = GCDAsyncUdpSocket(delegate: self, delegateQueue:DispatchQueue.main)
do { try socket.bind(toPort: PORT)} catch { print("")}
do { try socket.enableBroadcast(true)} catch { print("not able to brad cast")}
do { try socket.joinMulticastGroup(IP)} catch { print("joinMulticastGroup not proceed")}
do { try socket.beginReceiving()} catch { print("beginReceiving not proceed")}
}
//MARK:-GCDAsyncUdpSocketDelegate
func udpSocket(_ sock: GCDAsyncUdpSocket, didReceive data: Data, fromAddress address: Data, withFilterContext filterContext: Any?) {
print("incoming message: \(data)");
let signal:Signal = Signal.unarchive(d: data)
print("signal information : \n first \(signal.firstSignal) , second \(signal.secondSignal) \n third \(signal.thirdSignal) , fourth \(signal.fourthSignal)")
}
func udpSocket(_ sock: GCDAsyncUdpSocket, didNotConnect error: Error?) {
}
func udpSocketDidClose(_ sock: GCDAsyncUdpSocket, withError error: Error?) {
}
}
STEP 5 :- Sending Socket..
//Sending End...
class OutSocket: NSObject, GCDAsyncUdpSocketDelegate {
// let IP = "10.123.45.1"
let IP = "127.0.0.1"
let PORT:UInt16 = 5001
var socket:GCDAsyncUdpSocket!
override init(){
super.init()
}
func setupConnection(success:(()->())){
socket = GCDAsyncUdpSocket(delegate: self, delegateQueue:DispatchQueue.main)
do { try socket.bind(toPort: PORT)} catch { print("")}
do { try socket.connect(toHost:IP, onPort: PORT)} catch { print("joinMulticastGroup not proceed")}
do { try socket.beginReceiving()} catch { print("beginReceiving not proceed")}
success()
}
func send(signal:Signal){
let signalData = Signal.archive(w: signal)
socket.send(signalData, withTimeout: 2, tag: 0)
}
//MARK:- GCDAsyncUdpSocketDelegate
func udpSocket(_ sock: GCDAsyncUdpSocket, didConnectToAddress address: Data) {
print("didConnectToAddress");
}
func udpSocket(_ sock: GCDAsyncUdpSocket, didNotConnect error: Error?) {
if let _error = error {
print("didNotConnect \(_error )")
}
}
func udpSocket(_ sock: GCDAsyncUdpSocket, didNotSendDataWithTag tag: Int, dueToError error: Error?) {
print("didNotSendDataWithTag")
}
func udpSocket(_ sock: GCDAsyncUdpSocket, didSendDataWithTag tag: Int) {
print("didSendDataWithTag")
}
}
STEP 6 :- Your Signal Data which you will Send/Recieve
import Foundation
struct Signal {
var firstSignal:UInt16 = 20
var secondSignal:UInt16 = 30
var thirdSignal: UInt16 = 40
var fourthSignal: UInt16 = 50
static func archive(w:Signal) -> Data {
var fw = w
return Data(bytes: &fw, count: MemoryLayout<Signal>.stride)
}
static func unarchive(d:Data) -> Signal {
guard d.count == MemoryLayout<Signal>.stride else {
fatalError("BOOM!")
}
var s:Signal?
d.withUnsafeBytes({(bytes: UnsafePointer<Signal>)->Void in
s = UnsafePointer<Signal>(bytes).pointee
})
return s!
}
}