I'm trying connect to local esp8266 UDP server. SwiftSocket haven't documentation. CocoaAsyncSocket doesn't work. How to connect and send data to udp server? What i should do?
I wrote sample UDP python server and tried connect to them via SwiftSocket and CocoaAsyncSocket. I'm don't get feedback from app. Server don't receive connections. For example- one of the most attempts:
var connection = NWConnection(host: "255.255.255.255", port: 9093, using: .udp)
connection.stateUpdateHandler = { (newState) in
switch (newState) {
case .ready:
print("ready")
case .setup:
print("setup")
case .cancelled:
print("cancelled")
case .preparing:
print("Preparing")
default:
print("waiting or failed")
break
}
}
connection.start(queue: .global())
connection.send(content: "Xyu".data(using: String.Encoding.utf8), completion: NWConnection.SendCompletion.contentProcessed(({ (NWError) in
print(NWError)
})))
connection.receiveMessage { (data, context, isComplete, error) in
print("Got it")
print(data)
}
Can't connect to the server
This solution work for me! Thanks @Paulw11
Swift 4, XCode 10.1, iOS 12.0
Simple connect to the public UDP server (This is NOT optimal version but works):
import UIKit
import Network
class ViewController: UIViewController {
var connection: NWConnection?
var hostUDP: NWEndpoint.Host = "iperf.volia.net"
var portUDP: NWEndpoint.Port = 5201
override func viewDidLoad() {
super.viewDidLoad()
// Hack to wait until everything is set up
var x = 0
while(x<1000000000) {
x+=1
}
connectToUDP(hostUDP,portUDP)
}
func connectToUDP(_ hostUDP: NWEndpoint.Host, _ portUDP: NWEndpoint.Port) {
// Transmited message:
let messageToUDP = "Test message"
self.connection = NWConnection(host: hostUDP, port: portUDP, using: .udp)
self.connection?.stateUpdateHandler = { (newState) in
print("This is stateUpdateHandler:")
switch (newState) {
case .ready:
print("State: Ready\n")
self.sendUDP(messageToUDP)
self.receiveUDP()
case .setup:
print("State: Setup\n")
case .cancelled:
print("State: Cancelled\n")
case .preparing:
print("State: Preparing\n")
default:
print("ERROR! State not defined!\n")
}
}
self.connection?.start(queue: .global())
}
func sendUDP(_ content: Data) {
self.connection?.send(content: content, completion: NWConnection.SendCompletion.contentProcessed(({ (NWError) in
if (NWError == nil) {
print("Data was sent to UDP")
} else {
print("ERROR! Error when data (Type: Data) sending. NWError: \n \(NWError!)")
}
})))
}
func sendUDP(_ content: String) {
let contentToSendUDP = content.data(using: String.Encoding.utf8)
self.connection?.send(content: contentToSendUDP, completion: NWConnection.SendCompletion.contentProcessed(({ (NWError) in
if (NWError == nil) {
print("Data was sent to UDP")
} else {
print("ERROR! Error when data (Type: Data) sending. NWError: \n \(NWError!)")
}
})))
}
func receiveUDP() {
self.connection?.receiveMessage { (data, context, isComplete, error) in
if (isComplete) {
print("Receive is complete")
if (data != nil) {
let backToString = String(decoding: data!, as: UTF8.self)
print("Received message: \(backToString)")
} else {
print("Data == nil")
}
}
}
}
}
You need to wait until your connection is in the ready state before you try and send or receive any data. You will also need to hold a strong reference to your connection in a property to prevent it from being released as soon as the function exits.
var connection: NWConnection?
func someFunc() {
self.connection = NWConnection(host: "255.255.255.255", port: 9093, using: .udp)
self.connection?.stateUpdateHandler = { (newState) in
switch (newState) {
case .ready:
print("ready")
self.send()
self.receive()
case .setup:
print("setup")
case .cancelled:
print("cancelled")
case .preparing:
print("Preparing")
default:
print("waiting or failed")
}
}
self.connection?.start(queue: .global())
}
func send() {
self.connection?.send(content: "Test message".data(using: String.Encoding.utf8), completion: NWConnection.SendCompletion.contentProcessed(({ (NWError) in
print(NWError)
})))
}
func receive() {
self.connection?.receiveMessage { (data, context, isComplete, error) in
print("Got it")
print(data)
}
}