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iOS RXSwift如何将核心蓝牙连接到RX序列?

rx-swift core-bluetooth observable swift ios

Alex Stone · 技术社区 · 6 年前

我正在尝试创建一个可观察的序列来指示设备上蓝牙的状态。我在用 ReplaySubject<CBManagerState> 但是我很好奇是否有更好的东西,因为我听说了关于使用 onNext()

将回调委托连接到Rxswift可观测域的适当方法是什么?

class BluetoothStatusMonitor: NSObject, CBPeripheralManagerDelegate {
let bluetoothStatusSequence = ReplaySubject<CBManagerState>.create(bufferSize: 1)

var bluetoothPeripheralManager: CBPeripheralManager?

    func checkBluetoothStatus()
    {
        //silently check permissions, without alert

        let options = [CBCentralManagerOptionShowPowerAlertKey:0]
        bluetoothPeripheralManager = CBPeripheralManager(delegate: self, queue: nil, options: options)

    }
    func peripheralManagerDidUpdateState(_ peripheral: CBPeripheralManager) {

        bluetoothStatusSequence.onNext(peripheral.state)
    }
}

1 回复 | 直到 6 年前

Daniel T. 6 年前

这正是受试者擅长做的事情。它们主要用于将非RX代码转换为RX代码。也就是说,Rxcococa有 DelegateProxy 设计用于处理大量必要工作以正确处理委托的类型。很难弄清楚如何实现一个,但是一旦你掌握了它的窍门,它们就非常有用了…

我不得不承认,大多数代码对我来说都是黑色的魔法,但它确实有效。我尽量在下面的评论中解释。

import RxSwift
import RxCocoa
import CoreBluetooth

    // The HasDelegate protocol is an associated type for the DelegateProxyType
extension CBPeripheralManager: HasDelegate {
    public typealias Delegate = CBPeripheralManagerDelegate
}

class CBPeripheralManagerDelegateProxy
    : DelegateProxy<CBPeripheralManager, CBPeripheralManagerDelegate>
    , DelegateProxyType
    , CBPeripheralManagerDelegate {

    init(parentObject: CBPeripheralManager) {
        super.init(parentObject: parentObject, delegateProxy: CBPeripheralManagerDelegateProxy.self)
    }

    deinit {
        _didUpdateState.onCompleted()
    }

    static func registerKnownImplementations() {
        register { CBPeripheralManagerDelegateProxy(parentObject: $0) }
    }

        // a couple of static functions for getting and setting a delegate on the object.
    static func currentDelegate(for object: CBPeripheralManager) -> CBPeripheralManagerDelegate? {
        return object.delegate
    }

    static func setCurrentDelegate(_ delegate: CBPeripheralManagerDelegate?, to object: CBPeripheralManager) {
        object.delegate = delegate
    }

        // required delegate functions must be implemented in the class. This is where Subjects come in.
    func peripheralManagerDidUpdateState(_ peripheral: CBPeripheralManager) {
        _didUpdateState.onNext(peripheral.state)
    }

    fileprivate let _didUpdateState = PublishSubject<CBManagerState>()
}

extension Reactive where Base: CBPeripheralManager {
    var delegate: CBPeripheralManagerDelegateProxy {
        return CBPeripheralManagerDelegateProxy.proxy(for: base)
    }

    var state: Observable<CBManagerState> {
        return delegate._didUpdateState
    }

    var didUpdateState: Observable<Void> {
        return delegate._didUpdateState.map { _ in }
    }

        // optional methods are setup using the `methodInvoked` function on the delegate
    var willRestoreState: Observable<[String: Any]> {
        return delegate.methodInvoked(#selector(CBPeripheralManagerDelegate.peripheralManager(_:willRestoreState:)))
            .map { $0[1] as! [String: Any] }
    }

    var didStartAdvertising: Observable<Error?> {
        return delegate.methodInvoked(#selector(CBPeripheralManagerDelegate.peripheralManagerDidStartAdvertising(_:error:)))
            .map { $0[1] as? Error }
    }

    // I didn't implement all of the optionals. Use the above as a template to implement the rest.
}

据我所知, methodInvoked 函数对对象执行一些元编程魔术,以便在运行时安装该方法。之所以这样做,是因为许多具有委托的IOS类实际上行为不同,这取决于该方法是否在委托上定义(不管该方法做什么),因此我们不希望简单地将协议中的每个方法都给代理。

当然,一旦你有了上面的内容。您可以使用外围设备管理器执行所有标准的Rx操作:

bluetoothManager.rx.state
    .subscribe(onNext: { state in print("current state:", state) })
    .disposed(by: disposeBag)

bluetoothManager.rx.didStartAdvertising
    .subscribe(onNext: { error in
        if let error = error {
            print("there was an error:", error)
        }
    }
    .disposed(by: disposeBag)