latitude and longitude points from MKPolyline

ios, mkmapview, mkpolyline

Solution

To get coordinates of the polyline from an `MKRoute`, use the `getCoordinates:range:` method. That method is in the `MKMultiPoint` class which `MKPolyline` inherits from.

That also means this works for any polyline -- whether it was created by you or by `MKDirections`.

You allocate a C array big enough to hold the number of coordinates you want and specify the range (eg. all points starting from the 0th).

Example:

//route is the MKRoute in this example
//but the polyline can be any MKPolyline

NSUInteger pointCount = route.polyline.pointCount;

//allocate a C array to hold this many points/coordinates...
CLLocationCoordinate2D *routeCoordinates 
    = malloc(pointCount * sizeof(CLLocationCoordinate2D));

//get the coordinates (all of them)...
[route.polyline getCoordinates:routeCoordinates 
                         range:NSMakeRange(0, pointCount)];

//this part just shows how to use the results...
NSLog(@"route pointCount = %d", pointCount);
for (int c=0; c < pointCount; c++)
{
    NSLog(@"routeCoordinates[%d] = %f, %f", 
        c, routeCoordinates[c].latitude, routeCoordinates[c].longitude);
}

//free the memory used by the C array when done with it...
free(routeCoordinates);

Depending on the route, be prepared for hundreds or thousands of coordinates.

Problem

I am trying to figure out a way to get all the latitude and longitude points from a MKPolyline drawn on a MKMapView on an iOS app. I know the MKPolyline does not store latitude and longitude points, but I am looking for a way to build an array of lat and long the MKPolyline would touch on the map. Anybody has specific possible solutions on this? Thank you EDIT: After seeing the first response (thank you) I think I need to explain better what my code is doing: - first I call "calculateDirectionsWithCompletionHandler" on a MKDirections object - I get back MKRoute object which has a "polyline" property. - then I call "addOverlay" on the mapview passing in the polyline from the MKRoute object That's all. So, I already have a polyline built for me. So I would like to get all the points found in the polyline somehow and map them to a lat and long...

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