我是新手,请耐心等待。
我试图在主ViewController类之外的扩展中启用按钮。基本上,我只希望按钮在用户的蓝牙天线打开且正在工作的情况下才能工作。看起来像这样:
extension UIViewController: CBCentralManagerDelegate {
//function called after manager is initialized, state of bluetooth on manager
public func centralManagerDidUpdateState(_ central:
CBCentralManager) {
switch central.state {
case .unknown:
print("central.state is .unknown")
case .resetting:
print("central.state is .resetting")
case .unsupported:
print("central.state is .unsupported")
case .unauthorized:
print("central.state is .unauthorized")
case .poweredOff:
print("central.state is .poweredOff")
case .poweredOn:
print("central.state is .poweredOn")
connectButton.isEnabled = true
@unknown default:
print("central.state is .unknown")
}
}
}
如您所见,在.poweredOn情况下,我尝试启用我的按钮。但是,我不断收到“使用 Unresolved 标识符”错误。这是我声明按钮的方式:class ViewController: UIViewController {
@IBOutlet var voltageOut: UILabel!
@IBOutlet public var connectButton: UIButton!
override func viewDidLoad() {
super.viewDidLoad()
connectButton.isEnabled = false
//initializing manager
myVars.centralManager = CBCentralManager(delegate: self, queue: nil)
}
@IBAction func connectButton(_ sender: Any) {
connect()
}
}
我已经搜寻了好几个小时,尝试将类设为打开/公开状态,当我在类外声明按钮时,覆盖函数中的'connectButton.isEnabled = false'导致了另一个错误。如何在主ViewController类之外访问按钮? 最佳答案
您正在扩展基类UIViewController,而不是扩展子类ViewController。基类对您在子类中声明的属性一无所知。
更改
extension UIViewController: CBCentralManagerDelegate {
至extension ViewController: CBCentralManagerDelegate {