ios - CBCentralManager iOS10 和 iOS9

Question

所以我要迁移到 iOS10，但我还需要我的代码才能在 iOS9 上运行。我正在使用 CoreBluetooth 和 CBCentralManagerDelegate。我可以让我的代码适用于 iOS10，但我需要回退才能适用于 iOS9。

func centralManagerDidUpdateState(_ central: CBCentralManager) {
    if #available(iOS 10.0, *) {
        switch central.state{
        case CBManagerState.unauthorized:
            print("This app is not authorised to use Bluetooth low energy")
        case CBManagerState.poweredOff:
            print("Bluetooth is currently powered off.")
        case CBManagerState.poweredOn:
            print("Bluetooth is currently powered on and available to use.")
        default:break
        }
    } else {

        // Fallback on earlier versions
        switch central.state{
        case CBCentralManagerState.unauthorized:
            print("This app is not authorised to use Bluetooth low energy")
        case CBCentralManagerState.poweredOff:
            print("Bluetooth is currently powered off.")
        case CBCentralManagerState.poweredOn:
            print("Bluetooth is currently powered on and available to use.")
        default:break
        }
    }
}

我得到错误:

Enum case 'unauthorized' is not a member of type 'CBManagerState'

线上:

case CBCentralManagerState.unauthorized: 

以及 .poweredOff 和 .poweredOn。

我有什么想法可以让它在这两种情况下都起作用吗？

Answer 1

您可以简单地省略枚举类型名称并只使用.value。这将在没有警告的情况下编译，并且可以在 iOS 10 和更早版本上运行，因为底层原始值是兼容的。

func centralManagerDidUpdateState(_ central: CBCentralManager) {
        switch central.state{
        case .unauthorized:
            print("This app is not authorised to use Bluetooth low energy")
        case .poweredOff:
            print("Bluetooth is currently powered off.")
        case .poweredOn:
            print("Bluetooth is currently powered on and available to use.")
        default:break
        }
}