創建可觀察到的Observable

Question

我有一個返回observable的方法。

在這種方法中，我訂閱了rxbluetooth observable。它運作良好，除了onComplete永遠不會被調用。

這裏是我的代碼：

private func getWifiConfig() -> Observable<String?> { 

    return Observable.create { [ weak self ] observer in 

    if let strongSelf = self { 

     tileConnect.peripheral.connect() 
     .retry(.delayed(maxCount: 30, time: 1), scheduler: MainScheduler.instance) 
     .flatMap { $0.discoverServices([ strongSelf.serviceUUID ]) } 
     .flatMap { Observable.from($0) } 
     .flatMap { $0.discoverCharacteristics([ strongSelf.wifiCharacteristicUUID ])} 
     .flatMap { Observable.from($0) } 
     .flatMap { $0.readValue() } 
     .retry(.delayed(maxCount: 30, time: 1), scheduler: MainScheduler.instance) 
     .subscribe(onNext: { 
      if let data = $0.value { 
      if let configDelimitedString = String(data: data, encoding: .utf8) { 
       observer.onNext(configDelimitedString) 
      } 
      } 
     }, onError: { error in 
      LOG_SENSOR_MANAGER("getWifiConfigFromCharacteristic. onError: \(error.localizedDescription)") 
      observer.onError(error) 
     }, onCompleted: { 
      LOG_SENSOR_MANAGER("getWifiConfigFromCharacteristic. onCompleted") 
         observer.onCompleted() // <---- NEVER CALLED 
     }, onDisposed: { 
      LOG_SENSOR_MANAGER("getWifiConfigFromCharacteristic. onDisposed") // <---- NEVER CALLED 
     }) 
     .disposed(by: strongSelf.disposeBag) 
     } 

     return Disposables.create() 
    } 
    } 

你有一個想法，爲什麼？

Answer 1

你可以試試這個：

private func getWifiConfig() -> Observable<String?> { 

    return Observable.create { [ weak self ] observer in 

     if let strongSelf = self { 

      tileConnect.peripheral.connect() 
       .retry(.delayed(maxCount: 30, time: 1), scheduler: MainScheduler.instance) 
       .flatMap { $0.discoverServices([ strongSelf.serviceUUID ]) } 
       .flatMap { Observable.from($0) } 
       .flatMap { $0.discoverCharacteristics([ strongSelf.wifiCharacteristicUUID ])} 
       .flatMap { Observable.from($0) } 
       .flatMap { $0.readValue() } 
       .retry(.delayed(maxCount: 30, time: 1), scheduler: MainScheduler.instance) 
       .subscribe(onNext: { 
        if let data = $0.value { 
         if let configDelimitedString = String(data: data, encoding: .utf8) { 
          observer.onNext(configDelimitedString) 
          observer.onCompleted() // <- Call it here 
         } 
        } 
       }, onError: { error in 
        LOG_SENSOR_MANAGER("getWifiConfigFromCharacteristic. onError: \(error.localizedDescription)") 
        observer.onError(error) 
       }) 
       .disposed(by: strongSelf.disposeBag) 
     } 

     return Disposables.create() 
    } 
} 

編輯：改善外觀和感覺。您可以使用guard有很強的參考自我：

private func getWifiConfig() -> Observable<String?> { 

    return Observable.create { [ weak self ] observer in 

     guard let `self` = self else { return } // strong reference to self. Now you can use self as strongSelf 

     // subscription 
     let subscription = tileConnect.peripheral.connect() 
      .retry(.delayed(maxCount: 30, time: 1), scheduler: MainScheduler.instance) 
      .flatMap { $0.discoverServices([ self.serviceUUID ]) } 
      .flatMap { Observable.from($0) } 
      .flatMap { $0.discoverCharacteristics([ self.wifiCharacteristicUUID ])} 
      .flatMap { Observable.from($0) } 
      .flatMap { $0.readValue() } 
      .retry(.delayed(maxCount: 30, time: 1), scheduler: MainScheduler.instance) 
      .subscribe(onNext: { 
       if let data = $0.value, 
       let configDelimitedString = String(data: data, encoding: .utf8) { 

        observer.onNext(configDelimitedString) 
        observer.onCompleted() // <- Call it here 
       } 
      }, onError: { error in 
       LOG_SENSOR_MANAGER("getWifiConfigFromCharacteristic. onError: \(error.localizedDescription)") 
       observer.onError(error) 
      }) 


     // Dispose the subscription 
     return Disposables.create { 
      subscription.dispose() 
     } 
    } 
}