如何检查当前坐标是否在其他坐标的半径范围内答案

【问题标题】：How to check if current coordinates are within a radius of other coordinates如何检查当前坐标是否在其他坐标的半径范围内
【发布时间】：2012-02-16 16:01:28
【问题描述】：

我有一个固定位置的经纬度。我想检查另一个位置（纬度和经度）是否足够接近（50-100 米）到固定位置。我使用 iPhone 获取当前位置。

【问题讨论】：

标签： iphone objective-c ios google-maps google-maps-api-3

【解决方案1】：

以下是在 Swift 中使用 CoreLocation 的方法。您只需在 CLLocation 类型的位置上使用 .distance(from: ) 方法比较 2 个不同的位置。确保两个位置的类型均为CLLocation

import CoreLocation

let someOtherLocation: CLLocation = CLLocation(latitude: someOtherLat,
                                               longitude: someOtherLon)

guard let usersCurrentLocation: CLLocation = locationManager.location else { return }

                                                       // **the distance(from: ) is right here **
let distanceInMeters: CLLocationDistance = usersCurrentLocation.distance(from: someOtherLocation)

if distanceInMeters < 100 {

    // this user is pretty much in the same area as the otherLocation
} else {

   // this user is at least over 100 meters outside the otherLocation
}

这不是必需的，但也许您需要保存 lats 和 lons 以供以后进行另一个比较。我知道我需要他们

let usersCurrentLat: CLLocationDegrees = currentLocation.coordinate.latitude // not neccessary but this is how you get the lat
let usersCurrentLon: CLLocationDegrees = currentLocation.coordinate.longitude // not neccessary but this is how you get the lon

let someOtherLocationLat: CLLocationDegrees = someOtherLocationLocation.coordinate.latitude // not neccessary but this is how you get the lat
let someOtherLocationLon: CLLocationDegrees = someOtherLocationtLocation.coordinate.longitude // not neccessary but this is how you get the lon


let usersLocation: CLLocation = CLLocation(latitude: usersCurrentLat,
                                           longitude: usersCurrentLon)

let otherLocation: CLLocation = CLLocation(latitude: someOtherLocationLat,
                                           longitude: someOtherLocationLon)

【讨论】：

【解决方案2】：

distanceFromCurrentLocation = [userLocation distanceFromLocation:destinationlocation]/convertToKiloMeter;
if(distanceFromCurrentLocation < 100 && distanceFromLocation > .500)
{
    NSLog(@"Yeah, this place is inside my circle");
}
else
{
    NSLog(@"Oops!! its too far");
}

这会找到空中距离，或者我们可以说，只是直线距离。
希望您不是在寻找道路距离。

【讨论】：

【解决方案3】：

func distance(from location: CLLocation) -> CLLocationDistance

Documentation

【讨论】：

【解决方案4】：

CLLocation的方法– distanceFromLocation:正是你所需要的。

【讨论】：

【解决方案5】：

添加到 Deepukjayan 答案，在使用他的答案之前使用 CLLocation 定义参考：

CLLocation *montreal = [[CLLocation alloc] initWithLatitude:45.521731 longitude:-73.628679];

【讨论】：

【解决方案6】：

虽然我赞成空堆栈答案.. 如果您需要更多帮助，这里是代码..

成为 CLLocationManagerDelegate，然后在您的实现类中。

 - (void)locationManager:(CLLocationManager *)manager didUpdateToLocation:(CLLocation *)newLocation fromLocation:(CLLocation *)oldLocation{


            int distance = [newLocation distanceFromLocation:oldLocation];
            if(distance >50 && distance <100)
            {

            UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Distance"
                                                            message:[NSString stringWithFormat:@"%i meters",distance]
                                                           delegate:nil
                                                  cancelButtonTitle:@"OK"
                                                  otherButtonTitles:nil];
            [alert show];
            [alert release];
            }
        }
    }

【讨论】：

【解决方案7】：

CLLocation *location;// = init...;
double distance = [location distanceFromLocation:otherLoc]; //in meters

【讨论】：