CoreBluetooth 特征值被覆盖为零

Question

我已经创建了一个蓝牙代理并且蓝牙连接正确。

在我的蓝牙对象中，我调用了所需的函数：

// Characteristic being targeted
var writeCharacteristic: CBCharacteristic!

public func peripheral(_ peripheral: CBPeripheral, 
    didDiscoverCharacteristicsFor service: CBService, error: Error?) {
    guard let characteristics = service.characteristics else {
        return
    }
    print(characteristics)
    for characteristic in characteristics {
        switch (characteristic.uuid) {
        case (serialUUID) :
            print("serialPortRXCharacterUUID: \(service.uuid)")
            writeCharacteristic = characteristic  
        default:
            print("nothing")
        }
    }
}

检查调试器 writeCharacteristic 存储正确的特征，但是当我在 ViewController 中调用 writeToDevice 时。

// View Controllers function
@IBAction func writeToDevice(_ sender: UIButton) {
    bluetoothManager.writeToPeripheral(message: "Test", peripheral: peripheral)
}

writeToDevice 函数在蓝牙类对象中被调用如下：

func writeToPeripheral(message: String, peripheral: CBPeripheral) {
    if let data = message.data(using: String.Encoding.utf8) {
        let datareturn = String(bytes: data, encoding: .utf8)
        print(writeCharacteristic)
        peripheral.writeValue(data, for: writeCharacteristic!, type: .withoutResponse)
    }
}

在设备连接时，调试器 writeCharacteristic 从一个值开始，但在我从另一个视图控制器调用按钮后，writeCharacteristic 似乎又回到了nil。

Answer 1

根据@Larme 的评论，我意识到我正在创建 BLE 对象的第二个实例，因此实现单例模式将解决此问题。