我希望在mapView中显示一个指向点的路线,我使用此代码创建路线:
- (IBAction)backToYourCar {
MKPlacemark *sourcePlacemark = [[MKPlacemark alloc] initWithCoordinate:self.annotationForCar.coordinate addressDictionary:nil];
NSLog(@"coordiante : locationIniziale %f", sourcePlacemark.coordinate.latitude);
MKMapItem *carPosition = [[MKMapItem alloc] initWithPlacemark:sourcePlacemark];
MKMapItem *actualPosition = [MKMapItem mapItemForCurrentLocation];
NSLog(@"coordiante : source %f, ActualPosition %f", carPosition.placemark.coordinate.latitude ,actualPosition.placemark.coordinate.latitude);
MKDirectionsRequest *request = [[MKDirectionsRequest alloc] init];
request.source = actualPosition;
request.destination = carPosition;
request.requestsAlternateRoutes = YES;
MKDirections *directions = [[MKDirections alloc] initWithRequest:request];
[directions calculateDirectionsWithCompletionHandler:^(MKDirectionsResponse *response, NSError *error) {
if (error) {
NSLog(@"Error : %@", error);
}
else {
[self showDirections:response]; //response is provided by the CompletionHandler
}
}];
}
这用于在地图上显示路线:
- (void)showDirections:(MKDirectionsResponse *)response
{
for (MKRoute *route in response.routes) {
[self.mapView addOverlay:route.polyline level:MKOverlayLevelAboveRoads];
}
}
实际上这段代码什么也没做。
如果我尝试打印路线的距离,我会得到正确的值:
route distance: 1910.000000
然后路线是正确的,但我不明白为什么它没有出现在地图上!
有什么建议吗?
答案 0 :(得分:49)
self.mapView.delegate = self
)。MKMapViewDelegate
- (MKOverlayRenderer *)mapView:(MKMapView *)mapView rendererForOverlay(id<MKOverlay>)overlay
:这是我的实施:
- (MKOverlayRenderer *)mapView:(MKMapView *)mapView rendererForOverlay:(id<MKOverlay>)overlay
{
if ([overlay isKindOfClass:[MKPolyline class]]) {
MKPolyline *route = overlay;
MKPolylineRenderer *routeRenderer = [[MKPolylineRenderer alloc] initWithPolyline:route];
routeRenderer.strokeColor = [UIColor blueColor];
return routeRenderer;
}
else return nil;
}
在地图上添加折线时,委托会自动调用此方法。