Swift, how to call a function in other viewcontroller? - ios

Question

My program has two controllers, CallerTableViewController, FunctionViewController
Caller is in CallerTableViewController and the function is in FunctionViewController
Now screen is displaying FunctionViewController while the calling program is in CallerTableViewController, the calling program should call the function in FunctionViewController
How can I call the function which is displaying on screen?
Update:
this is actual program
import UIKit
import CoreBluetooth
class TableViewController: UITableViewController,
CBCentralManagerDelegate,
CBPeripheralDelegate {
var centralManager:CBCentralManager!
var connectingPeripheral:CBPeripheral!
var bleDeviceName = [String]()
var bleDevice=[CBPeripheral]()
override func viewDidLoad() {
super.viewDidLoad()
let centralManager = CBCentralManager(delegate: self, queue: nil)
centralManager.scanForPeripherals(withServices: nil, options: nil)
self.centralManager = centralManager;
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
}
// MARK: - Table view data source
override func numberOfSections(in tableView: UITableView) -> Int {
return 1
}
override func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return bleDevice.count
}
override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "oneCell", for: indexPath)
cell.textLabel?.text = bleDeviceName[indexPath.row]
return cell
}
override func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath){
var peripheral=bleDevice[indexPath.row]
self.centralManager.stopScan()
connectingPeripheral = peripheral
connectingPeripheral.delegate = self
centralManager.connect(connectingPeripheral, options: nil)
}
required init?(coder aDecoder: NSCoder) {
super.init(coder: aDecoder)
centralManager = CBCentralManager(delegate: self, queue: DispatchQueue.main)
}
func centralManagerDidUpdateState(_ central: CBCentralManager) {
print("--- centralManagerDidUpdateState")
switch central.state{
case .poweredOn:
let serviceUUIDs:[AnyObject] = [CBUUID(string: "1111")]
let lastPeripherals = centralManager.retrieveConnectedPeripherals(withServices: serviceUUIDs as! [CBUUID])
print(lastPeripherals.count)
if lastPeripherals.count > 0{
print("count>0")
let device = lastPeripherals.last! as CBPeripheral;
connectingPeripheral = device;
centralManager.connect(connectingPeripheral, options: nil)
}
else {
centralManager.scanForPeripherals(withServices:nil, options: nil)
}
case .poweredOff:
print("--- central state is powered off")
case .resetting:
print("--- central state is resetting")
case .unauthorized:
print("--- central state is unauthorized")
case .unknown:
print("--- central state is unknown")
case .unsupported:
print("--- central state is unsupported")
}
}
func centralManager(_ central: CBCentralManager, didDiscover peripheral: CBPeripheral, advertisementData: [String : Any], rssi RSSI: NSNumber) {
print("--- didDiscover peripheral")
if let localName = advertisementData[CBAdvertisementDataLocalNameKey] as? String{
bleDevice.append(peripheral)
bleDeviceName.append(localName)
DispatchQueue.main.async{
self.tableView.reloadData()
}
}else{
print("!!!--- can't unwrap advertisementData[CBAdvertisementDataLocalNameKey]")
}
}
func centralManager(_ central: CBCentralManager, didConnect peripheral: CBPeripheral) {
print("--- didConnectPeripheral")
peripheral.delegate = self
peripheral.discoverServices(nil)
print("--- peripheral state is \(peripheral.state)")
}
func peripheral(_ peripheral: CBPeripheral, didDiscoverServices error: Error?) {
if (error) != nil{
print("!!!--- error in didDiscoverServices: \(error?.localizedDescription)")
}
else {
print("--- error in didDiscoverServices")
for service in peripheral.services as [CBService]!{
print("before disc chara"+service.uuid.uuidString)
if service.uuid.uuidString=="11111111-1111-11111111-1111111111111" {
peripheral.discoverCharacteristics(nil, for: service)
print("disc chara")
}
}
}
}
func peripheral(_ peripheral: CBPeripheral, didDiscoverCharacteristicsFor service: CBService, error: Error?) {
if (error) != nil{
print("!!!--- error in didDiscoverCharacteristicsFor: \(error?.localizedDescription)")
}
else {
print("found charact: service"+service.uuid.uuidString)
if service.uuid == CBUUID(string: "11111111-1111-11111111-1111111111111"){
for characteristic in service.characteristics! as [CBCharacteristic]{
switch characteristic.uuid.uuidString{
case "00000000-0000-0000-0000-0000000000000":
print("Found Characteristic")
peripheral.setNotifyValue(true, for: characteristic)
default:
print()
}
}
}
}
}
func peripheral(_ peripheral: CBPeripheral, didUpdateValueFor characteristic: CBCharacteristic, error: Error?) {
//call function here
//call function here
//call function here
//call function here
//call function here
//call function here
//call function here
//call function here
//call function here
//call function here
//call function here
//call function here
}
}
// this is the function in FunctionViewController
func printTextField() {
print(textField.text)
}

Answer 1

You can try this,
Class from where call back is to send ->
var dismissCallBackBlock: (() -> Void)?
func dismissControllerCallBackBlock(completionBlock:#escaping () ->Void){
dismissCallBackBlock = completionBlock
}
Class where call back is received ->
classObj.dismissControllerCallBackBlock { (Bool) in
}
Hope, it works.

Answer 2

The problem is get the 'FunctionController' object .
You can try this :
let story = UIStoryboard.init(name: "YOUR_STORY_BOARD_NAME", bundle: Bundle.main);
let fvc = story.instantiateViewController(withIdentifier: "YOUR_VIEWCONTROLLER_IDENTIFIER");
fvc.someFunction();
You can find "YOUR_STORY_BOARD_NAME" on your file's list , usually to be "Main":
Choose your 'FunctionViewController' in the storyboard and find YOUR_VIEWCONTROLLER_IDENTIFIER here: