将CLLocationCoordinate2D存储到NSUserDefaults

Question

我是iphone开发的新手，我想将CLLocationCoordinate2D对象存储到NSUserDefaults。我在努力

    [defaults setObject:location forKey:@"userLocation"];

但是它给出了错误的‘发送CLLocationCoordinate2D到不兼容的id'参数。

那么如何将CLLocationCoordinate2D存储到NSUserDefaults中呢？谢谢。

Answer 1

正如公司的所说，

默认对象必须是属性列表，即NSData、NSString、NSNumber、NSDate、NSArray或NSDictionary的实例。

我用它来存储，

    NSNumber *lat = [NSNumber numberWithDouble:location.latitude];
    NSNumber *lon = [NSNumber numberWithDouble:location.longitude];
    NSDictionary *userLocation=@{@"lat":lat,@"long":lon};

    [[NSUserDefaults standardUserDefaults] setObject:userLocation forKey:@"userLocation"];
    [[NSUserDefaults standardUserDefaults] synchronize];

和access使用，

    NSDictionary *userLoc=[[NSUserDefaults standardUserDefaults] objectForKey:@"userLocation"];
    NSLog(@"lat %@",[userLoc objectForKey:@"lat"]);
    NSLog(@"long %@",[userLoc objectForKey:@"long"]);

Answer 2

这就是我要做的：

NSData *data = [NSData dataWithBytes:&coordinate length:sizeof(coordinate)];
[[NSUserDefaults standardUserDefaults] setObject:data forKey:@"key"];
[[NSUserDefaults standardUserDefaults] synchronize];

然后你可以像这样检索它：

NSData *data = [[NSUserDefaults standardUserDefaults] objectForKey:@"key"];
CLLocationCoordinate2D coordinate;
[data getBytes:&coordinate length:sizeof(coordinate)];

Answer 3

import CoreLocation

// Store an array of CLLocationCoordinate2D
func storeCoordinates(_ coordinates: [CLLocationCoordinate2D]) {
let locations = coordinates.map { coordinate -> CLLocation in
    return CLLocation(latitude: coordinate.latitude, longitude: coordinate.longitude)
}
let archived = NSKeyedArchiver.archivedData(withRootObject: locations)
UserDefaults.standard.set(archived, forKey: "coordinates")
UserDefaults.standard.synchronize()
}

// Return an array of CLLocationCoordinate2D
func loadCoordinates() -> [CLLocationCoordinate2D]? {
guard let archived = UserDefaults.standard.object(forKey: "coordinates") as? Data,
    let locations = NSKeyedUnarchiver.unarchiveObject(with: archived) as? [CLLocation] else {
        return nil
}

let coordinates = locations.map { location -> CLLocationCoordinate2D in
    return location.coordinate
}
        return coordinates
}

现在让我们测试实现：

let testCoordinates = [
CLLocationCoordinate2D(latitude: 0.123456789, longitude: 0.123456789),
CLLocationCoordinate2D(latitude: 1.123456789, longitude: 1.123456789),
CLLocationCoordinate2D(latitude: 2.123456789, longitude: 2.123456789)
]

self.storeCoordinates(testCoordinates)

let coordinates = loadCoordinates()
print(coordinates)