Question

我最近从Swift 3升级到Swift 4，iOS 10.3.3升级到iOS 11.1。我正在开发一个使用BLE进行双向通信的应用程序。工作流程如下：

1）外围 - 广告身份

2）CENTRAL - 接收身份（处理它......）

3）CENTRAL - 回应外围设备

4）外围 - 接收来自中央的回复

5）完成

我的代码在更新之前完美运行但现在却没有。在步骤4结束时，我执行以下行：

peripheral.writeValue(encryptedData!, for: characteristic, type: .withResponse)

这应该调用以下委托方法，但它不会：

public func peripheral(_ peripheral: CBPeripheral, didWriteValueFor descriptor: CBDescriptor, error: Error?) {
        print("Did Write")
        print("Error=\(error?.localizedDescription)")
    }

它也应该（并且正在调用）PERIPHERAL设备上的以下委托方法，但它不会：

public func peripheralManager(_ peripheral: CBPeripheralManager, didReceiveWrite requests: [CBATTRequest]) {
        print("did receive write request")
}

服务和特征设置如下：

let prefs = Preferences()
            let strServiceUUID = prefs.GetString(key: Preferences.PREF_IDENTITY_SERVICE_UUID, defaultVal: "")!
            let strCharacteristicUUID = prefs.GetString(key: Preferences.PREF_IDENTITY_CHARACTERISTIC_UUID, defaultVal: "")!
            print("ServiceUUID=\(strServiceUUID)")
            print("CharacteristicUUID=\(strCharacteristicUUID)")
            mServiceUUID = CBUUID(string: strServiceUUID)
            mCharacterUUID = CBUUID(string: strCharacteristicUUID)
            mCBBluetoothServices = CBMutableService(type: mServiceUUID, primary: true)

            //lets configure the data we want to advertise for
            var characteristics : [CBCharacteristic] = []

            //let strData : String = "933911"
            //let data = strData.data(using: .utf8)
            let cbProperties: CBCharacteristicProperties = [.read, .write, .notify]
            let cbPermissions: CBAttributePermissions = [.readable, .writeable]
            mIdentityObjectCharacteristic = CBMutableCharacteristic(type: mCharacterUUID,
                                                                    properties: cbProperties,
                                                                    value: nil,
                                                                    permissions: cbPermissions)


            characteristics.append(mIdentityObjectCharacteristic)
            mCBBluetoothServices.characteristics = characteristics
            mCBPeripheralManager.add(mCBBluetoothServices)

Answer 1

我不确定为什么升级操作系统和Swift版本会破坏您的代码，但是我觉得您可能使用了错误的委托方法？

尝试使用此

func peripheral(CBPeripheral, didWriteValueFor: CBCharacteristic, error: Error?)

而不是

func peripheral(CBPeripheral, didWriteValueFor: CBDescriptor, error: Error?)

Answer 2

Swift 4

如果有任何更新特性（例如读/写特性）。然后＆＃39; didUpdateValueFor＆＃39;代表打来电话。所以首先检查下面的委托方法。

func peripheral(_ peripheral: CBPeripheral, didUpdateValueFor characteristic: CBCharacteristic, error: Error?) {

    print("didUpdateValueForChar", characteristic)

    if let error1 = error{

        alertMSG(titleString: "Error", subTitleString: "Found error while read characteristic data, Plase try again", buttonTitle: "OK")

        print(error1)
    }
    else{

        print("Update Characteristic: ", characteristic)
    }
}

func peripheral(_ peripheral: CBPeripheral, didWriteValueFor characteristic: CBCharacteristic, error: Error?) {

    print("Write Characteristic :", characteristic)
}

Answer 3

雨燕5
iOS 13

一些要检查的东西：

请确保将外设的delegate设置为符合CBPeripheralDelegate协议的控制器（该控制器也应与实现peripheral(_:didWriteValueFor:error:)方法的控制器相同）。
确保您未指定.withoutResponse写入类型。

如this other answer所述，有两种非常相似的具有签名peripheral(_:didWriteValueFor:error:)的委托方法。确保您实施的是正确的。

写特征时：

writeValue(_:for:type:)：

func writeValue(_ data: Data, 
                for characteristic: CBCharacteristic, 
                type: CBCharacteristicWriteType)

peripheral(_:didWriteValueFor:error:)

func peripheral(_ peripheral: CBPeripheral, 
                didWriteValueFor characteristic: CBCharacteristic, 
                error: Error?)

写描述符时：

writeValue(_:for:)

func writeValue(_ data: Data, 
                for descriptor: CBDescriptor)

peripheral(_:didWriteValueFor:error:)

func peripheral(_ peripheral: CBPeripheral, 
                didWriteValueFor descriptor: CBDescriptor, 
                error: Error?)

很容易混淆两组写方法和委托方法。

由于您正在使用：

peripheral.writeValue(encryptedData!, for: characteristic, type: .withResponse)

写入和委托对的代码应如下所示：

class BluetoothController: CBCentralManagerDelegate, CBPeripheralDelegate {

    ...
   
    func writeSomething(to characteristic: CBCharacteristic, of peripheral: CBPeripheral) {
        let something = "1234"
        
        NSLog("Writing \(something) to \(characteristic.uuid.uuidString)")
        
        peripheral.delegate = self  // <===== You may have forgotten this?
        peripheral.writeValue(something.data(using: .utf8)!,
                              for: characteristic,
                              type: .withResponse)
    }

    ...

    func peripheral(_ peripheral: CBPeripheral, didWriteValueFor characteristic: CBCharacteristic, error: Error?) {
        if error != nil {
            NSLog("Write error: \(String(describing: error))")
        } else {
            NSLog("Wrote value to \(characteristic.uuid.uuidString)")
        }
    }
}

BLE外围代表未调用

3 个答案: