ios - 如何断开已连接的蓝牙设备

Question

所以我的问题是当我转到不同的 Storyboard时，我的 ble 外围设备保持与手机的连接:我用来扫描和连接 ble 外围设备的代码:

import Foundation
import UIKit
import CoreBluetooth


var txCharacteristic : CBCharacteristic?
var rxCharacteristic : CBCharacteristic?
var blePeripheral : CBPeripheral?
var characteristicASCIIValue = NSString()



class BLECentralViewController : UIViewController, CBCentralManagerDelegate, CBPeripheralDelegate, UITableViewDelegate, UITableViewDataSource{

    //Data
    var centralManager : CBCentralManager!
    var RSSIs = [NSNumber]()
    var data = NSMutableData()
    var writeData: String = ""
    var peripherals: [CBPeripheral] = []
    var characteristicValue = [CBUUID: NSData]()
    var timer = Timer()
    var characteristics = [String : CBCharacteristic]()

    //UI
    @IBOutlet weak var baseTableView: UITableView!
    @IBOutlet weak var refreshButton: UIBarButtonItem!

    @IBAction func refreshAction(_ sender: AnyObject) {
        disconnectFromDevice()
        self.peripherals = []
        self.RSSIs = []
        self.baseTableView.reloadData()
        startScan()
    }

    override func viewDidLoad() {
        super.viewDidLoad()
        self.baseTableView.delegate = self
        self.baseTableView.dataSource = self
        self.baseTableView.reloadData()

        /*Our key player in this app will be our CBCentralManager. CBCentralManager objects are used to manage discovered or connected remote peripheral devices (represented by CBPeripheral objects), including scanning for, discovering, and connecting to advertising peripherals.
         */
        centralManager = CBCentralManager(delegate: self, queue: nil)
        let backButton = UIBarButtonItem(title: "Disconnect", style: .plain, target: nil, action: nil)
        navigationItem.backBarButtonItem = backButton
    }

    override func viewDidAppear(_ animated: Bool) {
        disconnectFromDevice()
        super.viewDidAppear(animated)
        refreshScanView()
        print("View Cleared")
    }

    override func viewWillDisappear(_ animated: Bool) {
        super.viewWillDisappear(animated)
        print("Stop Scanning")
        centralManager?.stopScan()
    }

    /*Okay, now that we have our CBCentalManager up and running, it's time to start searching for devices. You can do this by calling the "scanForPeripherals" method.*/

    func startScan() {
        peripherals = []
        print("Now Scanning...")
        self.timer.invalidate()
        centralManager?.scanForPeripherals(withServices: nil , options: [CBCentralManagerScanOptionAllowDuplicatesKey:false])
        Timer.scheduledTimer(timeInterval: 3, target: self, selector: #selector(self.cancelScan), userInfo: nil, repeats: false)
    }

    /*We also need to stop scanning at some point so we'll also create a function that calls "stopScan"*/
    @objc func cancelScan() {
        self.centralManager?.stopScan()
        print("Scan Stopped")
        print("Number of Peripherals Found: \(peripherals.count)")
    }

    func refreshScanView() {
        baseTableView.reloadData()
    }

    //-Terminate all Peripheral Connection
    /*
     Call this when things either go wrong, or you're done with the connection.
     This cancels any subscriptions if there are any, or straight disconnects if not.
     (didUpdateNotificationStateForCharacteristic will cancel the connection if a subscription is involved)
     */
    func disconnectFromDevice () {
        if blePeripheral != nil {
            // We have a connection to the device but we are not subscribed to the Transfer Characteristic for some reason.
            // Therefore, we will just disconnect from the peripheral
            centralManager?.cancelPeripheralConnection(blePeripheral!)
        }
    }


    func restoreCentralManager() {
        //Restores Central Manager delegate if something went wrong
        centralManager?.delegate = self
    }

    /*
     Called when the central manager discovers a peripheral while scanning. Also, once peripheral is connected, cancel scanning.
     */
    func centralManager(_ central: CBCentralManager, didDiscover peripheral: CBPeripheral,advertisementData: [String : Any], rssi RSSI: NSNumber) {

        blePeripheral = peripheral
        self.peripherals.append(peripheral)
        self.RSSIs.append(RSSI)
        peripheral.delegate = self
        self.baseTableView.reloadData()
        if blePeripheral == nil {
            print("Found new pheripheral devices with services")
            print("Peripheral name: \(String(describing: peripheral.name))")
            print("**********************************")
            print ("Advertisement Data : \(advertisementData)")
        }
    }

    //Peripheral Connections: Connecting, Connected, Disconnected

    //-Connection
    func connectToDevice () {
        centralManager?.connect(blePeripheral!, options: nil)
        print("Good luck")
        print(blePeripheral!.discoverServices(nil))
        print("Good luck")


    }

    /*
     Invoked when a connection is successfully created with a peripheral.
     This method is invoked when a call to connect(_:options:) is successful. You typically implement this method to set the peripheral’s delegate and to discover its services.
     */
    //-Connected
    func centralManager(_ central: CBCentralManager, didConnect peripheral: CBPeripheral) {
        print("*****************************")
        print("Connection complete")
        print("Peripheral info: \(String(describing: blePeripheral))")

        //Stop Scan- We don't need to scan once we've connected to a peripheral. We got what we came for.
        centralManager?.stopScan()
        print("Scan Stopped")

        //Erase data that we might have
        data.length = 0

        //Discovery callback
        peripheral.delegate = self
        //Only look for services that matches transmit uuid
        peripheral.discoverServices([BLEService_UUID])


        //Once connected, move to new view controller to manager incoming and outgoing data
        let storyboard = UIStoryboard(name: "Main1", bundle: nil)

        let uartViewController = storyboard.instantiateViewController(withIdentifier: "UartModuleViewController") as! UartModuleViewController

        uartViewController.peripheral = peripheral

        navigationController?.pushViewController(uartViewController, animated: true)
    }

    /*
     Invoked when the central manager fails to create a connection with a peripheral.
     */

    func centralManager(_ central: CBCentralManager, didFailToConnect peripheral: CBPeripheral, error: Error?) {
        if error != nil {
            print("Failed to connect to peripheral")
            return
        }
    }

    func disconnectAllConnection() {
        centralManager.cancelPeripheralConnection(blePeripheral!)
    }

    /*
     Invoked when you discover the peripheral’s available services.
     This method is invoked when your app calls the discoverServices(_:) method. If the services of the peripheral are successfully discovered, you can access them through the peripheral’s services property. If successful, the error parameter is nil. If unsuccessful, the error parameter returns the cause of the failure.
     */
    func peripheral(_ peripheral: CBPeripheral, didDiscoverServices error: Error?) {
        print("*******************************************************AAA")

        if ((error) != nil) {
            print("Error discovering services: \(error!.localizedDescription)")
            return
        }

        guard let services = peripheral.services else {
            return
        }
        //We need to discover the all characteristic
        for service in services {

            peripheral.discoverCharacteristics(nil, for: service)
            print("god bless")
            print(peripheral.discoverCharacteristics(nil, for: service))
            print("god bless")
            // bleService = service
        }
        print("Discovered Services: \(services)")
    }

    /*
     Invoked when you discover the characteristics of a specified service.
     This method is invoked when your app calls the discoverCharacteristics(_:for:) method. If the characteristics of the specified service are successfully discovered, you can access them through the service's characteristics property. If successful, the error parameter is nil. If unsuccessful, the error parameter returns the cause of the failure.
     */

    func peripheral(_ peripheral: CBPeripheral, didDiscoverCharacteristicsFor service: CBService, error: Error?) {

        print("*******************************************************")

        if ((error) != nil) {
            print("Error discovering services: \(error!.localizedDescription)")
            return
        }

        guard let characteristics = service.characteristics else {
            return
        }

        print("Found \(characteristics.count) characteristics!")

        for characteristic in characteristics {
            //looks for the right characteristic

            if characteristic.uuid.isEqual(BLE_Characteristic_uuid_Rx)  {
                rxCharacteristic = characteristic

                //Once found, subscribe to the this particular characteristic...
                peripheral.setNotifyValue(true, for: rxCharacteristic!)
                // We can return after calling CBPeripheral.setNotifyValue because CBPeripheralDelegate's
                // didUpdateNotificationStateForCharacteristic method will be called automatically
                peripheral.readValue(for: characteristic)
                print("Rx Characteristic: \(characteristic.uuid)")
            }
            if characteristic.uuid.isEqual(BLE_Characteristic_uuid_Tx){
                txCharacteristic = characteristic
                print("Tx Characteristic: \(characteristic.uuid)")
            }
            peripheral.discoverDescriptors(for: characteristic)
        }
    }

    // Getting Values From Characteristic

    /*After you've found a characteristic of a service that you are interested in, you can read the characteristic's value by calling the peripheral "readValueForCharacteristic" method within the "didDiscoverCharacteristicsFor service" delegate.
     */
    func peripheral(_ peripheral: CBPeripheral, didUpdateValueFor characteristic: CBCharacteristic, error: Error?) {

        if characteristic == rxCharacteristic {
            if let ASCIIstring = NSString(data: characteristic.value!, encoding: String.Encoding.utf8.rawValue) {
                characteristicASCIIValue = ASCIIstring
                print("Value Recieved: \((characteristicASCIIValue as String))")
                NotificationCenter.default.post(name:NSNotification.Name(rawValue: "Notify"), object: nil)

            }
        }
    }


    func peripheral(_ peripheral: CBPeripheral, didDiscoverDescriptorsFor characteristic: CBCharacteristic, error: Error?) {
        print("*******************************************************")

        if error != nil {
            print("\(error.debugDescription)")
            return
        }
        if ((characteristic.descriptors) != nil) {

            for x in characteristic.descriptors!{
                let descript = x as CBDescriptor?
                print("function name: DidDiscoverDescriptorForChar \(String(describing: descript?.description))")
                print("Rx Value \(String(describing: rxCharacteristic?.value))")
                print("Tx Value \(String(describing: txCharacteristic?.value))")
            }
        }
    }


    func peripheral(_ peripheral: CBPeripheral, didUpdateNotificationStateFor characteristic: CBCharacteristic, error: Error?) {
        print("*******************************************************")

        if (error != nil) {
            print("Error changing notification state:\(String(describing: error?.localizedDescription))")

        } else {
            print("Characteristic's value subscribed")
        }

        if (characteristic.isNotifying) {
            print ("Subscribed. Notification has begun for: \(characteristic.uuid)")
        }
    }



    func centralManager(_ central: CBCentralManager, didDisconnectPeripheral peripheral: CBPeripheral, error: Error?) {
        print("Disconnected")
    }


    func peripheral(_ peripheral: CBPeripheral, didWriteValueFor characteristic: CBCharacteristic, error: Error?) {
        guard error == nil else {
            print("Error discovering services: error")
            return
        }
        print("Message sent")
    }

    func peripheral(_ peripheral: CBPeripheral, didWriteValueFor descriptor: CBDescriptor, error: Error?) {
        guard error == nil else {
            print("Error discovering services: error")
            return
        }
        print("Succeeded!")
    }

    //Table View Functions
    func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
        return self.peripherals.count
    }

    func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
        //Connect to device where the peripheral is connected
        let cell = tableView.dequeueReusableCell(withIdentifier: "BlueCell") as! PeripheralTableViewCell
        let peripheral = self.peripherals[indexPath.row]
        let RSSI = self.RSSIs[indexPath.row]


        if peripheral.name == nil {
            cell.peripheralLabel.text = "nil"
        } else {
            cell.peripheralLabel.text = peripheral.name
        }
        cell.rssiLabel.text = "RSSI: \(RSSI)"

        return cell
    }

    func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
        blePeripheral = peripherals[indexPath.row]
        connectToDevice()
    }

    /*
     Invoked when the central manager’s state is updated.
     This is where we kick off the scan if Bluetooth is turned on.
     */
    func centralManagerDidUpdateState(_ central: CBCentralManager) {
        if central.state == CBManagerState.poweredOn {
            // We will just handle it the easy way here: if Bluetooth is on, proceed...start scan!
            print("Bluetooth Enabled")
            startScan()

        } else {
            //If Bluetooth is off, display a UI alert message saying "Bluetooth is not enable" and "Make sure that your bluetooth is turned on"
            print("Bluetooth Disabled- Make sure your Bluetooth is turned on")

            let alertVC = UIAlertController(title: "Bluetooth is not enabled", message: "Make sure that your bluetooth is turned on", preferredStyle: UIAlertControllerStyle.alert)
            let action = UIAlertAction(title: "ok", style: UIAlertActionStyle.default, handler: { (action: UIAlertAction) -> Void in
                self.dismiss(animated: true, completion: nil)
            })
            alertVC.addAction(action)
            self.present(alertVC, animated: true, completion: nil)
        }
    }
}

以及当我从另一个 View Controller 发送数据时的代码

import UIKit
import CoreBluetooth

class UartModuleViewController: UIViewController, CBPeripheralManagerDelegate, UITextViewDelegate, UITextFieldDelegate {

    //UI
    @IBOutlet weak var baseTextView: UITextView!
    @IBOutlet weak var sendButton: UIButton!
    @IBOutlet weak var inputTextField: UITextField!
    @IBOutlet weak var scrollView: UIScrollView!
    @IBOutlet weak var switchUI: UISwitch!
    //Data
    var centralManager : CBCentralManager!
    var peripheralManager: CBPeripheralManager?
    var peripheral: CBPeripheral!
    private var consoleAsciiText:NSAttributedString? = NSAttributedString(string: "")


    @IBAction func Discon(_ sender: Any) {
        disconnectFromDevice()
        print("Hello")

    }

    func disconnectFromDevice () {
            // We have a connection to the device but we are not subscribed to the Transfer Characteristic for some reason.
            // Therefore, we will just disconnect from the peripheral
            centralManager?.cancelPeripheralConnection(blePeripheral!)
    }

    override func viewDidLoad() {
        super.viewDidLoad()

        self.navigationItem.backBarButtonItem = UIBarButtonItem(title:"Back", style:.plain, target:nil, action:nil)

        //Create and start the peripheral manager
        peripheralManager = CBPeripheralManager(delegate: self, queue: nil)
        //-Notification for updating the text view with incoming text

    }

    override func viewDidAppear(_ animated: Bool) {


    }

    override func viewDidDisappear(_ animated: Bool) {
        // peripheralManager?.stopAdvertising()
        // self.peripheralManager = nil
        super.viewDidDisappear(animated)
        NotificationCenter.default.removeObserver(self)

    }


    @IBAction func clickSendAction(_ sender: AnyObject) {
        outgoingData()

    }
    @IBAction func S(_ sender: Any) {
        sends()
    }
    @IBAction func sendd(_ sender: Any) {
        sendd()
    }
    @IBAction func senda(_ sender: Any) {
        senda()
    }
    @IBAction func sendt(_ sender: Any) {
        sendt()
    }
    @IBAction func sendb(_ sender: Any) {
        sendb()
    }


    func outgoingData () {

        let inputText = "W"

        writeValue(data: inputText)


    }
    func sends () {

        let inputText = "S"

        writeValue(data: inputText)


    }

    func sendd () {

        let inputText = "D"

        writeValue(data: inputText)


    }
    func senda () {

        let inputText = "A"

        writeValue(data: inputText)


    }
    func sendt () {

        let inputText = "T"

        writeValue(data: inputText)


    }
    func sendb () {

        let inputText = "B"

        writeValue(data: inputText)


    }


    // Write functions
    func writeValue(data: String){
        let valueString = (data as NSString).data(using: String.Encoding.utf8.rawValue)
        //change the "data" to valueString
        if let blePeripheral = blePeripheral{
            if let txCharacteristic = txCharacteristic {
                blePeripheral.writeValue(valueString!, for: txCharacteristic, type: CBCharacteristicWriteType.withoutResponse)
            }
        }
    }

    func writeCharacteristic(val: Int8){
        var val = val
        let ns = NSData(bytes: &val, length: MemoryLayout<Int8>.size)
        blePeripheral!.writeValue(ns as Data, for: txCharacteristic!, type: CBCharacteristicWriteType.withResponse)
    }



    //MARK: UITextViewDelegate methods
    func textViewShouldBeginEditing(_ textView: UITextView) -> Bool {
        if textView === baseTextView {
            //tapping on consoleview dismisses keyboard
            inputTextField.resignFirstResponder()
            return false
        }
        return true
    }

    func textFieldDidBeginEditing(_ textField: UITextField) {
        scrollView.setContentOffset(CGPoint(x:0, y:250), animated: true)
    }

    func textFieldDidEndEditing(_ textField: UITextField) {
        scrollView.setContentOffset(CGPoint(x:0, y:0), animated: true)
    }

    func peripheralManagerDidUpdateState(_ peripheral: CBPeripheralManager) {
        if peripheral.state == .poweredOn {
            return
        }
        print("Peripheral manager is running")
    }

    //Check when someone subscribe to our characteristic, start sending the data
    func peripheralManager(_ peripheral: CBPeripheralManager, central: CBCentral, didSubscribeTo characteristic: CBCharacteristic) {
        print("Device subscribe to characteristic")
    }


    override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
        self.view.endEditing(true)
    }

    func textFieldShouldReturn(_ textField: UITextField) -> Bool {
        textField.resignFirstResponder()
        outgoingData()
        return(true)
    }

    func peripheralManagerDidStartAdvertising(_ peripheral: CBPeripheralManager, error: Error?) {
        if let error = error {
            print("\(error)")
            return
        }
    }
}

当我从第二个 View Controller 继续时，如何终止所有连接？

非常感谢大家

Answer 1

您可以在

中调用您的断开连接函数

override func prepareForSegue(segue: UIStoryboardSegue!, sender: AnyObject!)