ios - Swift 协议(protocol)委托(delegate)返回 nil

Question

我在 didConnect 函数中设置了一个断点来打印出委托(delegate)的值，它以 nil 的形式返回，我不知道为什么

@objc protocol KestrelDeviceConnectDelegate {
    func didConnect()
    func didDisconnect()
}

@objcMembers
class KestrelDeviceConnect: NSObject{


    static let singleton = KestrelDeviceConnect()
    public weak var delegate: KestrelDeviceConnectDelegate?

func centralManager(_ central: CBCentralManager, didConnect peripheral: CBPeripheral) {
        self.isInitialReading = false
        self.kestrelIsConnected = true
        kestrelPeripheral.discoverServices(nil)
        delegate?.didConnect()

    }

}

在目标 VC 中的 viewDidLoad 中

_kestrelVC = [[KestrelDeviceConnect alloc]init];
[_kestrelVC setDelegate:self];

Answer 1

问题是初始化一个新的 KestrelDeviceConnect 实例，所以 _kestrelVC = [[KestrelDeviceConnect alloc]init]; 起作用的是 _kestrelVC = [KestrelDeviceConnect单例]