快速将 CLLocation 转换为 CLLocationCoordinate2D

Question

嗨，在理解 swift 编程中的声明部分时遇到了很多麻烦。 我有代码行CLLocationCoordinate2D myCoordinate = myLocation.coordinate; 与我在 Swift 编程中声明的一样，但我遇到了错误

var location1:CLLocation! = locationManager1.location
var coordinate1:CLLocationCoordinate2D = location1.coordinate

致命错误：无法打开 Optional.None

Answer 1

location1 可以是nil，并且您必须在访问其属性之前检查它是否为nil，例如这个：

let locationManager1: CLLocationManager // your location manager

// ...

if let location1: CLLocation = locationManager1.location {
    var coordinate1: CLLocationCoordinate2D = location1.coordinate

    // ... proceed with the location and coordintes

} else {
    println("no location...")
}