使用MKPolyline在地图上绘制用户路由

Question

我是Objective-C的新手

在我的应用程序中，我正在尝试将用户绘制到地图上的路由。

这是我到目前为止所拥有的，只是让用户当前位置：

#import "StartCycleViewController.h"
#import "CrumbPath.h"

@interface StartCycleViewController ()
@property (nonatomic, strong) CLLocationManager *locationManager;
@property (nonatomic, strong) IBOutlet MKMapView *map;
@property (nonatomic, strong) UIView *containerView;


@end
@implementation StartCycleViewController
@synthesize cycleLocation = _cycleLocation;
@synthesize currentCycleLocation = _currentCycleLocation;



 - (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil
 {
    self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
    if (self) {
    // Custom initialization
    }
    return self;
 }
- (void)viewDidLoad
{
    [super viewDidLoad];
    [self startCycleLocation];
    _containerView = [[UIView alloc] initWithFrame:self.view.bounds];
    [self.view addSubview:self.containerView];
    [self.containerView addSubview:self.map];
    // Do any additional setup after loading the view.
}

- (void)dealloc
{
    self.locationManager.delegate = nil;
}

- (void)didReceiveMemoryWarning
{
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}

#pragma mark - startCycleLocation
- (void)startCycleLocation{
    if (!_cycleLocation){
        _cycleLocation = [[CLLocationManager alloc]init];
        _cycleLocation.desiredAccuracy = kCLLocationAccuracyBestForNavigation;
        _cycleLocation.distanceFilter = 10;
        _cycleLocation.delegate = self;
    }
    [_cycleLocation startUpdatingLocation];
}
- (void)locationManager:(CLLocationManager *)manager didUpdateToLocation:(CLLocation     *)newLocation fromLocation:(CLLocation *)oldLocation {
    NSLog(@"didUpdateToLocation: %@", newLocation);
    CLLocation *currentLocation = newLocation;
    if (currentLocation != nil) {
    self.longitudeLabel.text = [NSString stringWithFormat:@"%.8f",    currentLocation.coordinate.longitude];
    self.latitudeLabel.text = [NSString stringWithFormat:@"%.8f",    currentLocation.coordinate.latitude];
    }
}

- (void) locationManager:(CLLocationManager *)manager didFailWithError:(NSError *)error {
    NSLog(@"%@",error);
    if ( [error code] != kCLErrorLocationUnknown ){
        [self stopLocationManager];
    }
}
- (void) stopLocationManager {
    [self.cycleLocation stopUpdatingLocation];
}

@end

我在网上环顾四周，收集我应该使用MKPolyline并给予坐标。但是我只是不确定如何存储位置，然后将它们发送使用MKPolyline在应用程序运行时连续绘制点。

Answer 1

您应该只创建一个 NSMutableArray，以保持您在viewDidLoad中实例化的位置。因此，请使用didUpdateToLocation（或者，如果支持iOS 6及更高版本，则应使用didUpdateToLocations）只需在数组中添加一个位置，然后从该数组中构建一个MKPolyline，请在地图中添加该MKPolyline，然后删除旧的MKPolyline。或者，您可以将所有行段添加为单个MKPolyline对象，但是这个想法是相同的，创建一个模型以保持您的位置（例如NSMutableArray），然后将适当的MKPolyline对象添加到地图视图中。p>例如，您可以做类似：

的事情

#pragma mark - CLLocationManagerDelegate
- (void)locationManager:(CLLocationManager *)manager didUpdateLocations:(NSArray *)locations
{
    CLLocation *location = [locations lastObject];
    if (location.horizontalAccuracy < 0)
        return;
    [self.locations addObject:location];
    NSUInteger count = [self.locations count];
    if (count > 1) {
        CLLocationCoordinate2D coordinates[count];
        for (NSInteger i = 0; i < count; i++) {
            coordinates[i] = [(CLLocation *)self.locations[i] coordinate];
        }
        MKPolyline *oldPolyline = self.polyline;
        self.polyline = [MKPolyline polylineWithCoordinates:coordinates count:count];
        [self.mapView addOverlay:self.polyline];
        if (oldPolyline)
            [self.mapView removeOverlay:oldPolyline];
    }
}

并记住指定映射如何绘制MKPolyline。因此，将视图控制器设置为MKMapView的delegate，然后您可以执行以下操作：

#pragma mark - MKMapViewDelegate
- (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;
}
// for iOS versions prior to 7; see `rendererForOverlay` for iOS7 and later
- (MKOverlayView *)mapView:(MKMapView *)mapView viewForOverlay:(id <MKOverlay>)overlay
{
    if ([overlay isKindOfClass:[MKPolyline class]])
    {
        MKPolylineView *overlayView = [[MKPolylineView alloc] initWithPolyline:overlay];
        overlayView.strokeColor     = [[UIColor blueColor] colorWithAlphaComponent:0.7];
        overlayView.lineWidth       = 3;
        return overlayView;
    }
    return nil;
}