类不符合NSObjectProtocol

时间:2016-11-20 15:05:36

标签: swift class

我收到的错误是我的班级不符合NSObjectProtocol,我不知道这意味着什么。我已经实现了WCSessionDelegate的所有功能,所以这不是问题。有人知道问题是什么吗?谢谢!

import Foundation
import WatchConnectivity

class BatteryLevel: WCSessionDelegate {


    var session: WCSession? {
        didSet {
            if let session = session {
                session.delegate = self
                session.activate()
            }
        }
    }

    var batteryStatus = 0.0;

    func getBatteryLevel(){
        if WCSession.isSupported() {
            // 2
            session = WCSession.default()
            // 3
            session!.sendMessage(["getBatteryLevel": ""], replyHandler: { (response) -> Void in
                if (response["batteryLevel"] as? String) != nil {
                    self.batteryStatus = (response["batteryLevel"] as? Double)! * 100
                }
            }, errorHandler: { (error) -> Void in
                // 6
                print(error)
            })
        }}


    func session(_ session: WCSession, activationDidCompleteWith activationState: WCSessionActivationState, error: Error?) {
    }

    func session(_ session: WCSession, didReceiveMessage message: [String : Any]) {
    }
}

1 个答案:

答案 0 :(得分:188)

请参阅Why in swift we cannot adopt a protocol without inheritance a class from NSObject?

简而言之,WCSessionDelegate本身继承自NSObjectProtocol,因此您也需要在该协议中实现方法。实现这些方法的最简单方法是子类NSObject

class BatteryLevel: NSObject, WCSessionDelegate

请注意,您在此处理Obj-C API。