ios - 在ios中找到我的位置和一个点之间的距离

Question

我正在使用一种方法来获取我的位置:

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


CLLocation *currentLocation = newLocation;

NSLog(@"%@", currentLocation);}


//new method to find the distance
        -(void) zoomToNearestSpot: (NSArray *) spot location: (CLLocation *)myLocation
    {
        myLocation = currentLocation;

        spot = chSpot;

        for (int i=0; i< spot.count; i++)
        {
        ChargingSpots *mySpot = [spot objectAtIndex:i];

        CLLocation *thePoint = [[CLLocation alloc]initWithLatitude:[mySpot.LocationLat doubleValue] longitude:[mySpot.LocationLong doubleValue]];

        CLLocationDistance dist = [myLocation distanceFromLocation:thePoint];

            NSLog(@"%f", dist);


       you get here **distance** in meter so in assumption  **20 miles = 32187 meter** 

放条件如

if(distance <= 32187)
{
  // under 20 miles   you can add the zoom level
}
else
{
  // out of 20 miles
}



        }
    }

首先，我需要根据 map 上的编号缩小显示 map 上的所有地点，然后找到最近的地点并在其上放大相机。

Answer 1

你有更多的两个坐标

1) current (user Location)
2) another coordinate ..

在这里distanceFromLocation:方法用于获取两个位置之间的距离。

CLLocationDistance distance = [currentLOcation distanceFromLocation:anotherLocation];

例如你需要添加以下几行

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

  CLLocation *currentLocation = newLocation;

   for (int i=0; i<chSpot.count; i++)
 {

     ChargingSpots *spot = [chSpot objectAtIndex:i];
     NSString *locLat = spot.LocationLat;
     NSString *locLong = spot.LocationLong;

     CLLocation *LocationAtual = [[CLLocation alloc] initWithLatitude: locLat longitude: locLong];

     CLLocationDistance distanceBetween = [currentLocation
        distanceFromLocation: LocationAtual];

     NSString *tripString = [[NSString alloc] 
       initWithFormat:@"%f", 
       distanceBetween];

     NSLog(@"DIST: %f", tripString); 
   }

 }