在swift中CLLocation到CLLocationCoordinate2D

Question

你在快速编程中理解声明部分时遇到了很多麻烦。 我有一行代码CLLocationCoordinate2D myCoordinate = myLocation.coordinate; 和我在Swift编程中声明的一样，但是我遇到了错误

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 ，你必须在访问其属性之前检查它是否为nil ，例如：

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...")
}