Het volgende viewDidLoadzal (1) in te stellen twee locaties, (2) verwijder alle vorige annotaties, en (3) telefoonnummer van de gebruiker gedefinieerde helper functies (om de route punten te krijgen en trek de route).
-(void)viewDidLoad
{
[super viewDidLoad];
// Origin Location.
CLLocationCoordinate2D loc1;
loc1.latitude = 29.0167;
loc1.longitude = 77.3833;
Annotation *origin = [[Annotation alloc] initWithTitle:@"loc1" subTitle:@"Home1" andCoordinate:loc1];
[objMapView addAnnotation:origin];
// Destination Location.
CLLocationCoordinate2D loc2;
loc2.latitude = 19.076000;
loc2.longitude = 72.877670;
Annotation *destination = [[Annotation alloc] initWithTitle:@"loc2" subTitle:@"Home2" andCoordinate:loc2];
[objMapView addAnnotation:destination];
if(arrRoutePoints) // Remove all annotations
[objMapView removeAnnotations:[objMapView annotations]];
arrRoutePoints = [self getRoutePointFrom:origin to:destination];
[self drawRoute];
[self centerMap];
}
Het volgende is de MKMapViewDelegatemethode, die overlay trekt (iOS 4.0 en hoger).
/* MKMapViewDelegate Meth0d -- for viewForOverlay*/
- (MKOverlayView*)mapView:(MKMapView*)theMapView viewForOverlay:(id <MKOverlay>)overlay
{
MKPolylineView *view = [[MKPolylineView alloc] initWithPolyline:objPolyline];
view.fillColor = [UIColor blackColor];
view.strokeColor = [UIColor blackColor];
view.lineWidth = 4;
return view;
}
De volgende functie zal zowel de locaties te krijgen en voor te bereiden URL om alle routepunten te krijgen. En natuurlijk, zal stringWithURL bellen.
/* This will get the route coordinates from the Google API. */
- (NSArray*)getRoutePointFrom:(Annotation *)origin to:(Annotation *)destination
{
NSString* saddr = [NSString stringWithFormat:@"%f,%f", origin.coordinate.latitude, origin.coordinate.longitude];
NSString* daddr = [NSString stringWithFormat:@"%f,%f", destination.coordinate.latitude, destination.coordinate.longitude];
NSString* apiUrlStr = [NSString stringWithFormat:@"http://maps.google.com/maps?output=dragdir&saddr=%@&daddr=%@", saddr, daddr];
NSURL* apiUrl = [NSURL URLWithString:apiUrlStr];
NSError *error;
NSString *apiResponse = [NSString stringWithContentsOfURL:apiUrl encoding:NSUTF8StringEncoding error:&error];
NSString* encodedPoints = [apiResponse stringByMatching:@"points:\\\"([^\\\"]*)\\\"" capture:1L];
return [self decodePolyLine:[encodedPoints mutableCopy]];
}
De volgende code is de echte magie (decoder voor de reactie die we kregen van de API). Ik zou die code niet wijzigen, tenzij ik weet wat ik doe :)
- (NSMutableArray *)decodePolyLine:(NSMutableString *)encodedString
{
[encodedString replaceOccurrencesOfString:@"\\\\" withString:@"\\"
options:NSLiteralSearch
range:NSMakeRange(0, [encodedString length])];
NSInteger len = [encodedString length];
NSInteger index = 0;
NSMutableArray *array = [[NSMutableArray alloc] init];
NSInteger lat=0;
NSInteger lng=0;
while (index < len) {
NSInteger b;
NSInteger shift = 0;
NSInteger result = 0;
do {
b = [encodedString characterAtIndex:index++] - 63;
result |= (b & 0x1f) << shift;
shift += 5;
} while (b >= 0x20);
NSInteger dlat = ((result & 1) ? ~(result >> 1) : (result >> 1));
lat += dlat;
shift = 0;
result = 0;
do {
b = [encodedString characterAtIndex:index++] - 63;
result |= (b & 0x1f) << shift;
shift += 5;
} while (b >= 0x20);
NSInteger dlng = ((result & 1) ? ~(result >> 1) : (result >> 1));
lng += dlng;
NSNumber *latitude = [[NSNumber alloc] initWithFloat:lat * 1e-5];
NSNumber *longitude = [[NSNumber alloc] initWithFloat:lng * 1e-5];
printf("\n[%f,", [latitude doubleValue]);
printf("%f]", [longitude doubleValue]);
CLLocation *loc = [[CLLocation alloc] initWithLatitude:[latitude floatValue] longitude:[longitude floatValue]];
[array addObject:loc];
}
return array;
}
Deze functie zal een route te trekken en zal een overlay toe te voegen.
- (void)drawRoute
{
int numPoints = [arrRoutePoints count];
if (numPoints > 1)
{
CLLocationCoordinate2D* coords = malloc(numPoints * sizeof(CLLocationCoordinate2D));
for (int i = 0; i < numPoints; i++)
{
CLLocation* current = [arrRoutePoints objectAtIndex:i];
coords[i] = current.coordinate;
}
self.objPolyline = [MKPolyline polylineWithCoordinates:coords count:numPoints];
free(coords);
[objMapView addOverlay:objPolyline];
[objMapView setNeedsDisplay];
}
}
De volgende code zal centreren uitlijnen van de kaart.
- (void)centerMap
{
MKCoordinateRegion region;
CLLocationDegrees maxLat = -90;
CLLocationDegrees maxLon = -180;
CLLocationDegrees minLat = 90;
CLLocationDegrees minLon = 180;
for(int idx = 0; idx < arrRoutePoints.count; idx++)
{
CLLocation* currentLocation = [arrRoutePoints objectAtIndex:idx];
if(currentLocation.coordinate.latitude > maxLat)
maxLat = currentLocation.coordinate.latitude;
if(currentLocation.coordinate.latitude < minLat)
minLat = currentLocation.coordinate.latitude;
if(currentLocation.coordinate.longitude > maxLon)
maxLon = currentLocation.coordinate.longitude;
if(currentLocation.coordinate.longitude < minLon)
minLon = currentLocation.coordinate.longitude;
}
region.center.latitude = (maxLat + minLat) / 2;
region.center.longitude = (maxLon + minLon) / 2;
region.span.latitudeDelta = maxLat - minLat;
region.span.longitudeDelta = maxLon - minLon;
[objMapView setRegion:region animated:YES];
}
Ik hoop dat dit zou iemand te helpen.
