使用 API 中的坐标绘制路线

Posted 2023-03-05

【中文标题】使用 API 中的坐标绘制路线

【英文标题】：Draw route using coordinates from API

【发布时间】：2014-12-16 22:28:27

【问题描述】：

我正在使用 transportAPI 获取从一个点到另一个点的路线。我打算在地图视图中选择后绘制路线。选择了一条首选路线，我遍历它的数组以获取所有坐标。

问题是我无法使用 MKPolyline 绘制路线。下面是我的代码；

- (void)viewDidLoad

    [super viewDidLoad];

  //  NSLog(@"selected route: %@",selectedRoute.routeParts);
    NSMutableArray * cordArray = [[NSMutableArray alloc]init];
    for (int i = 0;i < selectedRoute.routeParts.count; i++)
    
        NSMutableArray * cords =[[selectedRoute.routeParts objectAtIndex:i]objectForKey:@"coordinates"];

         for (int c = 0;c < cords.count; c++)
         

             double latitude = [[[cords objectAtIndex:c]objectAtIndex:1]doubleValue];
             double longitude = [[[cords objectAtIndex:c]objectAtIndex:0]doubleValue];
             CLLocation * location = [[CLLocation alloc] initWithLatitude:latitude longitude:longitude];
             [cordArray addObject:location];
             NSLog(@"coordiantes %@",cordArray);
         
    

            CLLocationCoordinate2D coordinates[cordArray.count];
            //int i = 0;
            int numPoints = [cordArray count];
            for (int i = 0; i<numPoints;i++)
            
                CLLocation * current = [cordArray objectAtIndex:i];
                coordinates[i] = current.coordinate;
            

            // create a polyline with all cooridnates
            self.polyline = [MKPolyline polylineWithCoordinates:coordinates count:numPoints];
            [self.mapView addOverlay:self.polyline];
            [mapView setDelegate:self];



- (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;
 

坐标数组的sn-p；

oordiantes (
    "<+51.51756000,-0.12033000> +/- 0.00m (speed -1.00 mps / course -1.00) @ 12/16/14, 10:04:19 PM Greenwich Mean Time"
)
2014-12-16 22:04:19.545 MeetUp[16434:1366070] coordiantes (
    "<+51.51756000,-0.12033000> +/- 0.00m (speed -1.00 mps / course -1.00) @ 12/16/14, 10:04:19 PM Greenwich Mean Time",
    "<+51.51865000,-0.12089000> +/- 0.00m (speed -1.00 mps / course -1.00) @ 12/16/14, 10:04:19 PM Greenwich Mean Time"
)
2014-12-16 22:04:19.547 MeetUp[16434:1366070] coordiantes (
    "<+51.51756000,-0.12033000> +/- 0.00m (speed -1.00 mps / course -1.00) @ 12/16/14, 10:04:19 PM Greenwich Mean Time",
    "<+51.51865000,-0.12089000> +/- 0.00m (speed -1.00 mps / course -1.00) @ 12/16/14, 10:04:19 PM Greenwich Mean Time",
    "<+51.51912000,-0.12129000> +/- 0.00m (speed -1.00 mps / course -1.00) @ 12/16/14, 10:04:19 PM Greenwich Mean Time"
)

我认为返回的坐标应该只是这样，例如：

[+51.51756000,-0.12033000]
[51.51865000,-0.12089000]
[+51.51912000,-0.12129000]

我做错了什么？

【参考方案1】：

尝试在添加叠加层之前设置地图的委托，例如：

// create a polyline with all cooridnates
self.polyline = [MKPolyline polylineWithCoordinates:coordinates count:numPoints];
[mapView setDelegate:self]; // <-- move this line to before addOverlay
[self.mapView addOverlay:self.polyline];

至于你的coordiantes数组日志，是正确的。

【讨论】：

这就像一个魅力，愚蠢的我，谢谢你。如果我想放大这些点，我该如何实现？谢谢

@DrPatience 查看setRegion:animated::developer.apple.com/library/mac/documentation/MapKit/Reference/…: