Question

在我获取用户位置的函数中，我创建了预授权，以便在授权消息之前发出警报，以免失去从用户那里获得必要权限的机会。

func getCurrentLocation() {
// Init LocationManager
locationManager = CLLocationManager()
locationManager.delegate = self
locationManager.desiredAccuracy = 
kCLLocationAccuracyThreeKilometers;

let alert = UIAlertController(title: "Allow Loction Services?",
message: "This allows the app to your loction",
preferredStyle: .alert)

let ok = UIAlertAction(title: "Allow", style: .default, handler: { 
(action) -> Void in
self.showHUD("loading...")

if locationManager.responds(to: 
#selector(CLLocationManager.requestWhenInUseAuthorization)) {
locationManager.requestAlwaysAuthorization()
}}
self.hideHUD()
)
}



let cancel = UIAlertAction(title: "Not Now", style: .destructive, 
handler: { (action) -> Void in })

alert.addAction(ok); alert.addAction(cancel)
present(alert, animated: true, completion: nil)

locationManager.startUpdatingLocation()
}

在以下部分：

let ok = UIAlertAction(title: "Allow", style: .default, handler: { (action) -> Void in self.showHUD("loading...")

错误弹出我们说“没有更多上下文的表达类型是不明确的”

Answer 1

Swift编译器给出了这个错误，因为语句self.hideHUD()超出了标记完成处理程序块的大括号。

我怀疑上面的线上没有两个花括号，你需要一个花括号，而另一个在后隐藏HUD：

.......
        locationManager.requestAlwaysAuthorization()
    }
    self.hideHUD()
}
........

Swift预先允许覆盖

1 个答案: