为在Swift中使用的Objective-C类添加便捷的初始化程序扩展

Question

我使用iOS-nRF-Toolbox中的一些代码

ScannedPeripheral类包含一个初始化程序

+ (ScannedPeripheral*) initWithPeripheral:(CBPeripheral*)peripheral rssi:(int)RSSI isPeripheralConnected:(BOOL)isConnected NS_REFINED_FOR_SWIFT;

我可以这样在Swift中调用它

ScannedPeripheral.initWithPeripheral(peripheral, rssi: 0, isPeripheralConnected: true)

但这看起来并不好。 苹果如何采取可可API？

我试图用NS_REFINED_FOR_SWIFT标记初始化程序，并添加了Swift扩展名：

extension ScannedPeripheral {
    convenience init(peripheral: CBPeripheral, rssi: Int32, isPeripheralConnected: Bool) {
        ScannedPeripheral.__initWithPeripheral(peripheral, rssi: rssi, isPeripheralConnected: isPeripheralConnected);
    }
}

但是现在出现一个错误，指出Self.init isn't called on all paths before returning from initializer 。

Answer 1

我认为最好为ScannedPeripheral而不是扩展编写子类，因为扩展可能不支持初始化程序和重写方法。

样品

class SubClassScannedPeripheral: ScannedPeripheral {
  override class func initWithPeripheral(peripheral: CBPeripheral, rssi: Int32, isPeripheralConnected: Bool) -> ScannedPeripheral {
   return ScannedPeripheral.initWithPeripheral(peripheral, rssi: rssi, isPeripheralConnected: isPeripheralConnected);
}
}