在mapview iOS 6中绘制折线

Posted 2023-02-23

【中文标题】在mapview iOS 6中绘制折线

【英文标题】：Draw polyline in mapview iOS 6

【发布时间】：2013-04-23 10:42:30

【问题描述】：

您好，我正在做一个应用程序，它必须显示带有路线的地图。我解析了一个 Json 以获得绘制折线的点。我在网上找到了一个代码来绘制这条折线。我在这个链接上找到的代码：http://iosguy.com/2012/05/22/tracing-routes-with-mapkit/

上面写着“创建 MKPolyline 注释”我试图在我的应用程序中导入它，但是我在创建坐标数组时遇到了问题。我的方法是这样的：

- (void)createMKpolylineAnnotation 
NSInteger numberOfSteps = self.path.count;

CLLocationCoordinate2D *coords = malloc(sizeof(CLLocationCoordinate2D) * numberOfSteps);
for (NSInteger index = 0; index < numberOfSteps; index++) 
    CLLocation *location = [self.path objectAtIndex:index];
    CLLocationCoordinate2D coordinate = location.coordinate;
    coords[index] = coordinate;


MKPolyline *polyLine = [MKPolyline polylineWithCoordinates:coords count:numberOfSteps];
[self.mapView addOverlay:polyLine];

当我尝试查看 coords 的值仅在第一次设置时，这是为什么呢？ 你能帮我解决这个问题还是我应该换一种模式？

我在这里发布处理地图视图的视图控制器的代码。

MapViewController.h

#import <UIKit/UIKit.h>
#import <MapKit/MapKit.h>

@interface MapViewController : UIViewController <MKMapViewDelegate>
@property (weak, nonatomic) IBOutlet MKMapView *mapView;

@property (nonatomic, strong) NSString *fromCity;
@property (nonatomic, strong) NSString *toCity;

- (IBAction)chooseKindOfMap:(id)sender;
@end

MapViewController.m

#import "MapViewController.h"
#import "AppDelegate.h"
#import "PlaceAnnotation.h"

@interface MapViewController ()

@property (nonatomic, strong)NSMutableArray *mapAnnotation;
@property (nonatomic) BOOL needUpdateRegion;
@property (nonatomic, strong)NSMutableArray *path;

@end

@implementation MapViewController

- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil

    self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
    if (self) 
        // Custom initialization
    
    return self;


- (void)viewDidLoad

    [super viewDidLoad];
    [self parseGoogleJsonToObtainPointsForPolyline];
    [self.mapView setDelegate:self];
    self.needUpdateRegion = YES;
    //[self centerMap];
    self.mapAnnotation = [[NSMutableArray alloc]initWithCapacity:2];
    AppDelegate *appDelegate = (AppDelegate*)[[UIApplication sharedApplication]delegate];
    NSLog(@"%d", appDelegate.dataForMap.count);
    NSArray* coords = [self getCoords:appDelegate.dataForMap];
    NSLog(@"coords = %@", coords);
    PlaceAnnotation *fromPlace = [[PlaceAnnotation alloc] initWithCoordinateAndName:coords[0] andLong:coords[1] andName:self.fromCity];
    PlaceAnnotation *toPlace = [[PlaceAnnotation alloc] initWithCoordinateAndName:coords[2] andLong:coords[3] andName:self.toCity];

    [self.mapAnnotation insertObject:fromPlace atIndex:0];
    [self.mapAnnotation insertObject:toPlace atIndex:1];
    NSLog(@"mapAnnotation.count: %d", self.mapAnnotation.count);

    if (self.mapAnnotation) 
        [self.mapView removeAnnotations:self.mapView.annotations];
    

    [self.mapView addAnnotation:self.mapAnnotation[0]];
    [self.mapView addAnnotation:self.mapAnnotation[1]];
    NSLog(@"MapAnnotation = %@", self.mapView.annotations);
    [self updateRegion];
    [self createMKpolylineAnnotation];


//- (void)viewDidAppear:(BOOL)animated 
//    [super viewDidAppear:animated];
//    if (self.needUpdateRegion) [self updateRegion];
//


- (void)didReceiveMemoryWarning

    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.


- (MKAnnotationView*)mapView:(MKMapView *)mapView viewForAnnotation:(id<MKAnnotation>)annotation 
    MKPinAnnotationView *pin = [[MKPinAnnotationView alloc] initWithAnnotation:annotation reuseIdentifier:nil];
    pin.pinColor = MKPinAnnotationColorRed;
    return pin;


- (void)mapView:(MKMapView *)mapView didAddAnnotationViews:(NSArray *)views 
    MKPinAnnotationView *ulv = [mapView viewForAnnotation:mapView.userLocation];
    ulv.hidden = YES;


- (NSArray*)getCoords:(NSDictionary*)data 
    NSArray *legs = [data objectForKey:@"legs"];
    NSDictionary *firstZero = [legs objectAtIndex:0];
    NSDictionary *endLocation = [firstZero objectForKey:@"end_location"];
    NSDictionary *startLocation = [firstZero objectForKey:@"start_location"];
    NSString *latFrom = [startLocation objectForKey:@"lat"];
    NSString *lngFrom = [startLocation objectForKey:@"lng"];
    NSString *latTo = [endLocation objectForKey:@"lat"];
    NSString *lngTo = [endLocation objectForKey:@"lng"];
    return @[latFrom,lngFrom,latTo,lngTo];


- (void)centerMap 
    MKCoordinateRegion region;
    region.center.latitude = 41.178654;
    region.center.longitude = 11.843262;
    region.span.latitudeDelta = 11.070406;
    region.span.longitudeDelta = 12.744629;

    [self.mapView setRegion:region];


- (IBAction)chooseKindOfMap:(id)sender 
    if ([sender tag] == 0) 
        self.mapView.mapType = MKMapTypeStandard;
    
    if ([sender tag] == 1) 
        self.mapView.mapType = MKMapTypeSatellite;
    
    if ([sender tag] == 2) 
        self.mapView.mapType = MKMapTypeHybrid;
    


- (void)updateRegion

    self.needUpdateRegion = NO;
    CGRect boundingRect;
    BOOL started = NO;
    for (id <MKAnnotation> annotation in self.mapView.annotations) 
        CGRect annotationRect = CGRectMake(annotation.coordinate.latitude, annotation.coordinate.longitude, 0, 0);
        if (!started) 
            started = YES;
            boundingRect = annotationRect;
         else 
            boundingRect = CGRectUnion(boundingRect, annotationRect);
        
    
    if (started) 
        boundingRect = CGRectInset(boundingRect, -0.2, -0.2);
        if ((boundingRect.size.width < 20) && (boundingRect.size.height < 20)) 
            MKCoordinateRegion region;
            region.center.latitude = boundingRect.origin.x + boundingRect.size.width / 2;
            region.center.longitude = boundingRect.origin.y + boundingRect.size.height / 2;
            region.span.latitudeDelta = boundingRect.size.width;
            region.span.longitudeDelta = boundingRect.size.height;
            [self.mapView setRegion:region animated:YES];
        
    


- (void)parseGoogleJsonToObtainPointsForPolyline 
    NSDictionary *polyline;
    NSMutableArray *points = [[NSMutableArray alloc]init];;

    AppDelegate *appDelegate = (AppDelegate*)[[UIApplication sharedApplication]delegate];
    NSArray *legs = [appDelegate.dataForMap objectForKey:@"legs"];
    NSDictionary *firstZero =[legs objectAtIndex:0];
    NSArray *steps = [firstZero objectForKey:@"steps"];
    for (int i = 0; i < steps.count; i++) 
        polyline = [steps[i] objectForKey:@"polyline"];
        [points addObject:polyline[@"points"]];
        NSLog(@"POINTS = %@", polyline[@"points"]);
        self.path = [self decodePolyLine:points[i]];
    
    NSLog(@"path = %@", self.path);


-(NSMutableArray *)decodePolyLine:(NSString *)encodedStr 
    NSMutableString *encoded = [[NSMutableString alloc] initWithCapacity:[encodedStr length]];
    [encoded appendString:encodedStr];
    [encoded replaceOccurrencesOfString:@"\\\\" withString:@"\\"
                                options:NSLiteralSearch
                                  range:NSMakeRange(0, [encoded length])];
    NSInteger len = [encoded 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 = [encoded 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 = [encoded 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];

        CLLocation *location = [[CLLocation alloc] initWithLatitude:[latitude floatValue] longitude:[longitude floatValue]];
        [array addObject:location];
    

    return array;


- (MKOverlayView *)mapView:(MKMapView *)mapView viewForOverlay:(id <MKOverlay>)overlay 
    MKPolylineView *polylineView = [[MKPolylineView alloc] initWithPolyline:overlay];
    polylineView.strokeColor = [UIColor redColor];
    polylineView.lineWidth = 1.0;

    return polylineView;


- (void)createMKpolylineAnnotation 
    NSInteger numberOfSteps = self.path.count;

    CLLocationCoordinate2D *coords = malloc(sizeof(CLLocationCoordinate2D) * numberOfSteps);
    for (NSInteger index = 0; index < numberOfSteps; index++) 
        CLLocation *location = [self.path objectAtIndex:index];
        CLLocationCoordinate2D coordinate = location.coordinate;
        coords[index] = coordinate;
    

    MKPolyline *polyLine = [MKPolyline polylineWithCoordinates:coords count:numberOfSteps];
    [self.mapView addOverlay:polyLine];

@end

我使用 AppDelegate 来拥有 Json（我在另一个类中解析它）

【参考方案1】：

Here 是一个教程如何将折线添加到 mapView。希望这会有所帮助！

编辑：

很遗憾，上面提供的链接现已损坏，我无法找到所指的教程。

【参考方案2】：

简单，只需复制粘贴我的代码并修改一些变量

- (IBAction)traceRoute:(UIButton *)sender 
 double latDouble = 39.7540615;
    double lngDouble = -8.8059587;

//    double latDouble = [self.sheetDetail.data.locationLat doubleValue];
//    double lngDouble = [self.sheetDetail.data.locationLng doubleValue];

    CLLocationCoordinate2D c2D = CLLocationCoordinate2DMake(latDouble, lngDouble);

    MKPlacemark *placemark = [[MKPlacemark alloc] initWithCoordinate:c2D addressDictionary:nil];
    MKMapItem *mapItem = [[MKMapItem alloc] initWithPlacemark:placemark];
    [mapItem setName:@"Mobile Edge"];


    MKPlacemark *placemark2;
    MKMapItem *mapItem2;
    if(kIS_OS_8_OR_LATER) 
        placemark2 = [[MKPlacemark alloc] initWithCoordinate:_userLoc addressDictionary:nil];
        mapItem2 = [[MKMapItem alloc] initWithPlacemark:placemark2];
        [mapItem2 setName:@"Me"];
     else 
        placemark2 = [[MKPlacemark alloc] initWithCoordinate:_mapView.userLocation.coordinate addressDictionary:nil];
        mapItem2 = [[MKMapItem alloc] initWithPlacemark:placemark2];
        [mapItem2 setName:@"Me"];
    

    MKDirectionsRequest *request = [[MKDirectionsRequest alloc] init];
    request.source = mapItem2;
    request.destination = mapItem;
    request.requestsAlternateRoutes = NO;
    MKDirections *directions = [[MKDirections alloc] initWithRequest:request];

    [directions calculateDirectionsWithCompletionHandler:
     ^(MKDirectionsResponse *response, NSError *error) 
         if (error) 
             // Handle error
             [[NSNotificationCenter defaultCenter] postNotificationName:@"finishedLocationRoute" object:nil];

             UIAlertView *alert = [[UIAlertView alloc] initWithTitle: NSLocalizedString(@"Route error title", nil)
                                                             message: NSLocalizedString(@"Route error", nil)
                                                            delegate:self
                                                   cancelButtonTitle:@"OK"
                                                   otherButtonTitles:nil];
             [alert show];

          else 
             for (MKRoute *route in response.routes)
             

                 //MKMapPoint middlePoint = route.polyline.points[route.polyline.pointCount/2];
                 //[self createAndAddAnnotationForCoordinate:MKCoordinateForMapPoint(middlePoint) andRoute:route];
                 [self.mapView addOverlay:route.polyline level:MKOverlayLevelAboveRoads];
             

             //notifies parent menu
             //[[NSNotificationCenter defaultCenter] postNotificationName:@"finishedLocationRoute" object:nil];

         
     ];


- (MKOverlayRenderer *)mapView:(MKMapView *)mapView rendererForOverlay:(id)overlay


    if (![overlay isKindOfClass:[MKPolygon class]]) 

        MKPolyline *route = overlay;
        MKPolylineRenderer *renderer = [[MKPolylineRenderer alloc] initWithPolyline:route];
        renderer.strokeColor = [UIColor blueColor];
        renderer.lineWidth = 5.0;
        return renderer;

     else 

        return nil;