如何在mapkit中显示两个位置之间的路径

Question

我想在mapkit中显示两个位置的距离，我已经尝试了我的过程，它不显示两个位置之间的距离。尝试下面的代码它不工作，谁能帮助我在编码。

MKMapView *   mapView = [[MKMapView alloc]initWithFrame:CGRectMake(0, 294, 320, 122)];
mapView.showsUserLocation = YES;
mapView.delegate = self;
MKDirectionsRequest *request = [[MKDirectionsRequest alloc] init];
 MKPlacemark *placemark1 = [[MKPlacemark alloc] initWithCoordinate:CLLocationCoordinate2DMake(9.9176458, 78.1228237) addressDictionary:nil];
[request setSource:[[MKMapItem alloc] initWithPlacemark:placemark1]];

MKPlacemark *placemark = [[MKPlacemark alloc] initWithCoordinate:CLLocationCoordinate2DMake(13.0475604, 80.2089535) addressDictionary:nil];
request.destination = [[MKMapItem alloc] initWithPlacemark:placemark];


// [request setDestination:myMapItem];
    [request setTransportType:MKDirectionsTransportTypeAutomobile]; // This can be limited to automobile and walking directions.
    [request setRequestsAlternateRoutes:YES]; // Gives you several route options.
    MKDirections *directions = [[MKDirections alloc] initWithRequest:request];
    [directions calculateDirectionsWithCompletionHandler:^(MKDirectionsResponse *response, NSError *error) {
        if (!error) {
            for (MKRoute *route in [response routes]) {
                [mapView addOverlay:[route polyline] level:MKOverlayLevelAboveRoads]; // Draws the route above roads, but below labels.
                // You can also get turn-by-turn steps, distance, advisory notices, ETA, etc by accessing various route properties.
            }
        }
    }];
[self.view addSubview:mapView];



- (MKOverlayRenderer *)mapView:(MKMapView *)mapView rendererForOverlay:(id < MKOverlay >)overlay
{
    MKPolylineRenderer *renderer =
    [[MKPolylineRenderer alloc] initWithOverlay:overlay];
    renderer.strokeColor = [UIColor blueColor];
    renderer.lineWidth = 5.0;
    return renderer;
}

请帮帮我。

Answer 1

如果您在-calculateDirectionsWithCompletionHandler:中选中error

[directions calculateDirectionsWithCompletionHandler:^(MKDirectionsResponse *response, NSError *error) {
    if (!error) {
        for (MKRoute *route in [response routes]) {
            [mapView addOverlay:[route polyline] level:MKOverlayLevelAboveRoads]; // Draws the route above roads, but below labels.
            // You can also get turn-by-turn steps, distance, advisory notices, ETA, etc by accessing various route properties.
        }
    }
    else {
        NSLog(@"%@", error);
    }
}];

你可能会看到

Error Domain=MKErrorDomain Code=5 "Directions Not Available“UserInfo=0x7fefe3bb5660 {无法确定到最近道路的NSLocalizedFailureReason=A路线。，MKErrorGEOError=-403，MKDirectionsErrorCode=6，NSLocalizedDescription=Directions不可用}

这意味着不可能从给定位置计算方向。

Answer 2

这是我的代码；我使用CLLocationManager委托来计算两个位置和MKMapView委托之间的距离。这是我的代码，它可能会对你有所帮助。

- (void)locationManager:(CLLocationManager *)manager didUpdateLocations:(NSArray *)location{
float distance = 0.0f;
NSMutableArray *locationArray = [[NSMutableArray alloc] init];
for (CLLocation *newLocation in location) {
    [locationArray addObject:newLocation];
}

for (int i = 0 ; i < locationArray.count; i++) {
    CLLocation *newLocation = [locationArray objectAtIndex:i];
    distance += [newLocation distanceFromLocation:[locationArray objectAtIndex:i+1]];
}         
NSLog(@"%f",distance);
CLLocationCoordinate2D cordinates [locationsArray.count];
MKPolyline *userLocationsPolyLine = [MKPolyline polylineWithCoordinates:cordinates count:locationsArray.count];
[userMapView setDelegate:self];
[userMapView addOverlay:userLocationsPolyLine];

}

- (MKOverlayRenderer *)mapView:(MKMapView *)mapView rendererForOverlay:(id<MKOverlay>)overlay{    
    if ([overlay isKindOfClass:[MKPolyline class]]){
        MKPolylineRenderer *renderer = [[MKPolylineRenderer alloc] initWithPolyline:overlay];
        renderer.strokeColor = [[UIColor blueColor] colorWithAlphaComponent:0.7];
        renderer.lineWidth   = 3;
        return renderer;
    }
    return nil;
}