How to work with UDP sockets in iOS, swift?

Question

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 shoul

Answer 1

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)
    }
}