IOS SwiftUI Reconnect TCP Connection - swift

Question

i create a TCP Server in C and i want a communication between an Iphone and PC.
That work. But when i close the Server or connection lost i must restart the APP on Iphone to make a new connection a simple start() don´t work, the error ist, "Cannot set state changed handler after cancel".
The second problem is, i create two Textfields for IP Adress and Port, how can i give this values to my network class and make new connection?
Thanks for help, here ist my code:
RMTApp.swift
//
// RMTApp.swift
// RMT
//
// Created by Erik on 13.07.21.
//
import SwiftUI
#main
struct RMTApp: App {
var body: some Scene {
WindowGroup {
ContentView()
}
}
}
ContentView.swift
//
// ContentView.swift
// RMT
//
// Created by Erik on 13.07.21.
//
import SwiftUI
import UserNotifications
class State_button: ObservableObject
{
#Published var strg_value: String = ""
#Published var temp_cnt: Int32 = 0
func requst_notification()
{
}
func test()
{
}
func button_connect()
{
strg_value = "Verbinden..."
}
func button_disconnect()
{
strg_value = ""
}
func counter()
{
temp_cnt = temp_cnt + 1;
}
}
struct ContentView: View {
#State private var IP_ADRESS: String = "192.168.5.1"
#State private var PORT: String = "1234"
#ObservedObject var state_button = State_button()
#StateObject var network = Network(hostName: "192.168.178.28", port: 1234)
#State private var switch_connect = false
#State private var isEditing = false
#State private var textfield: String = "Du bist ein String"
let generator = UINotificationFeedbackGenerator()
var body: some View {
Color.black
.ignoresSafeArea()
.overlay(
VStack()
{
HStack
{
Image("AG")
.resizable()
.scaledToFit()
.frame(width: 32.0, height: 32.0)
Text(" TCP TEST ")
.font(.largeTitle)
.fontWeight(.bold)
.foregroundColor(Color.white)
.multilineTextAlignment(.leading)
.padding()
//.padding(.bottom, 50)
.background(Color.black)
//.border(Color.white, width: 5)
Image("AG")
.resizable()
.scaledToFit()
.frame(width: 32.0, height: 32.0)
}
HStack
{
Group
{
TextField("IP Adress", text: $IP_ADRESS)
{
isEditing in
self.isEditing = isEditing
}
onCommit:
{
print("Eingegeben: \(IP_ADRESS)")
self.generator.notificationOccurred(.success)
}
.autocapitalization(.none)
.disableAutocorrection(true)
.border(Color.white)
.foregroundColor(.white)
.font(Font.system(size: 30, design: .default))
.multilineTextAlignment(.center)
//Text(test)
// .foregroundColor(isEditing ? .red : .blue)
TextField("Port", text: $PORT)
{
isEditing in
self.isEditing = isEditing
}
onCommit:
{
print("Eingegeben: \(PORT)")
self.generator.notificationOccurred(.success)
}
.autocapitalization(.none)
.disableAutocorrection(true)
.border(Color.white)
.foregroundColor(.white)
.font(Font.system(size: 30, design: .default))
.multilineTextAlignment(.center)
//Text(test)
// .foregroundColor(isEditing ? .red : .blue)
}//VSTACK EA field
}//Group
Toggle("Verbinden", isOn: $switch_connect)
.foregroundColor(Color.white)
.toggleStyle(SwitchToggleStyle(tint: network.connection_status ? Color.green : Color.red))
.padding(6)
//.position(x: 180, y: 60)
.border(Color.white, width: 1)
.font(Font.system(size: 30, design: .default))
.onChange(of: switch_connect)
{ value in
self.generator.notificationOccurred(.success)
if switch_connect
{
if network.connection_status == false
{
network.start()
}
}
else { }
//network.start()
}
Text("Empfangen:")
.foregroundColor(Color.white)
.font(Font.system(size: 30, design: .default))
ScrollView()
{
VStack()
{
Text(String(network.textstorage))
.lineLimit(nil)
//printf("Item \($0)")
}
.frame(maxWidth: .infinity)
}
.border(Color.blue)
.frame(minWidth: 0, maxWidth: .infinity, minHeight: 0, maxHeight: 200)
.foregroundColor(Color.white)
.background(Color.black)
.font(Font.system(size: 15, design: .default))
.lineLimit(5)
//.multilineTextAlignment(.trailing)
Spacer()
Button(action:{
let vibrate = UIImpactFeedbackGenerator(style: .heavy)
vibrate.impactOccurred()
network.stop()
network.start()
})
{
Text("Test")
.font(.headline)
.fontWeight(/*#START_MENU_TOKEN#*/.bold/*#END_MENU_TOKEN#*/)
.foregroundColor(Color.black
)
}
.padding(10)
.padding(.trailing, 100) //right
.padding(.leading, 100) //left
.multilineTextAlignment(.center)
.cornerRadius(8)
.background(RoundedRectangle(cornerRadius: 8).fill(Color.blue))
HStack
{
Button(action:{
network.cc()
let testx = " DasIstEinTest"
self.network.rec_val_state = false
if network.textstorage.count > 50
{
for _ in 1...testx.count
{
network.textstorage.remove(at: network.textstorage.startIndex)
}
}
network.textstorage = network.textstorage + testx;
let vibrate = UIImpactFeedbackGenerator(style: .heavy)
vibrate.impactOccurred() })
{
Text("Verbinden")
.font(.headline)
.fontWeight(/*#START_MENU_TOKEN#*/.bold/*#END_MENU_TOKEN#*/)
.foregroundColor(Color.black
)
.padding(5)
.multilineTextAlignment(.center)
.cornerRadius(5)
.background(RoundedRectangle(cornerRadius: 8).fill(Color.green))
//.position(x: 60, y: 100)
}
//.buttonStyle(BorderlessButtonStyle());
Button(action:{network.textstorage = "";
self.network.rec_val_state = false;
let vibrate = UIImpactFeedbackGenerator(style: .heavy)
vibrate.impactOccurred()
network.stop()
})
{
Text("Löschen")
.font(.headline)
.fontWeight(/*#START_MENU_TOKEN#*/.bold/*#END_MENU_TOKEN#*/)
.foregroundColor(Color.black
)
} //Button disconnect
.padding(5)
.multilineTextAlignment(.center)
.cornerRadius(5)
.background(RoundedRectangle(cornerRadius: 8).fill(Color.red))
//.position(x: 30, y: 100)
Button(action:{ network.send(line: "Was geht ab??");
let vibrate = UIImpactFeedbackGenerator(style: .heavy)
vibrate.impactOccurred()
})
{
Text("Test")
.font(.headline)
.fontWeight(/*#START_MENU_TOKEN#*/.bold/*#END_MENU_TOKEN#*/)
.foregroundColor(Color.black
)
}
.padding(5)
.padding(.trailing, 35) //right
.padding(.leading, 35) //left
.multilineTextAlignment(.center)
.cornerRadius(0)
.background(RoundedRectangle(cornerRadius: 8).fill(Color.blue))
//.position(x: 30, y: 100)
}//HSTACK
}//VSTACK
)//Color Black
}//body view
}//Struct
struct SwiftUIView_Previews: PreviewProvider {
static var previews: some View {
ContentView()
}
}
Network.swift
//
// Network.swift
// RMT
//
// Created by Erik on 15.07.21.
//
import Foundation
import Network
class Network : ObservableObject {
init(hostName: String, port: Int) {
let host = NWEndpoint.Host(hostName)
let port = NWEndpoint.Port("\(port)")!
self.connection = NWConnection(host: host, port: port, using: .tcp)
}
var connection: NWConnection
var rec_val : String = "" //Rec Network Data
var textstorage : String = "" //Saves complete Network Data
let textstorage_max : Int = 250 //Max size of textStorage
#Published var rec_val_state = false //Variable set when Data is aviable to show on view
#Published var connection_status = false //When connect true else false
var IP_ADRESS : String = "192.168.178.28"
func start() {
NSLog("will start")
self.connection.stateUpdateHandler = self.didChange(state:)
self.startReceive()
self.connection.start(queue: .main)
}
func stop() {
self.connection.cancel()
NSLog("did stop")
}
func cc()
{
print("XTREAME")
self.connection = NWConnection(host: NWEndpoint.Host(IP_ADRESS), port: 1234, using: .tcp)
//self.connection.restart()
}
private func didChange(state: NWConnection.State) {
switch state {
case .setup:
break
case .waiting(let error):
NSLog("is waiting: %#", "\(error)")
case .preparing:
break
case .ready:
connection_status = true
break
case .failed(let error):
NSLog("did fail, error: %#", "\(error)")
connection_status = false
self.stop()
case .cancelled:
NSLog("was cancelled")
connection_status = false
self.stop()
#unknown default:
break
}
}
private func startReceive() {
self.connection.receive(minimumIncompleteLength: 1, maximumLength: 65536) { data, _, isDone, error in
if let data = data, !data.isEmpty {
self.rec_val = String(data: data, encoding: .utf8)!
if self.textstorage.count > self.textstorage_max
{
for _ in 1...self.rec_val.count
{
self.textstorage.remove(at: self.textstorage.startIndex)
}
}
self.textstorage = self.textstorage + self.rec_val
self.rec_val_state = true
print(self.rec_val)
}
if let error = error {
NSLog("did receive, error: %#", "\(error)")
self.stop()
return
}
if isDone {
NSLog("did receive, EOF")
self.stop()
return
}
self.startReceive()
}
}
func send(line: String) {
let data = Data("\(line)\r\n".utf8)
self.connection.send(content: data, completion: NWConnection.SendCompletion.contentProcessed { error in
if let error = error {
NSLog("did send, error: %#", "\(error)")
self.stop()
} else {
NSLog("did send, data: %#", data as NSData)
}
})
}
static func run() -> Never {
let m = Network(hostName: "192.168.5.1", port: 1234)
m.start()
let t = DispatchSource.makeTimerSource(queue: .main)
var counter = 20
t.setEventHandler {
m.send(line: "\(counter) bottles of beer on the wall.")
counter -= 1
if counter == 0 {
m.stop()
exit(EXIT_SUCCESS)
}
}
t.schedule(wallDeadline: .now() + 1.0, repeating: 1.0)
t.activate()
dispatchMain()
}
}
Greetings!