如何在 x 个移动注释之间画线？

Question

我是 xcode 的新手，我正在开发一个使用 mkmap 进行车辆跟踪的 iOS 应用程序我需要根据车辆移动每 5 秒在注释之间画一条线，我的问题是它只是第一次画线第二次刷新间隔它不起作用我的代码如下，

- (void)viewDidLoad
{
   [super viewDidLoad];
   aTimer = [NSTimer scheduledTimerWithTimeInterval:5
                                                      target:self
                                                    selector:@selector(timerFired:)
                                                    userInfo:nil
                                                     repeats:YES];
}
-(void)timerFired:(NSTimer *) theTimer
{
    NSArray *existingpoints = MapViewC.annotations;
    if ([existingpoints count])
        [MapViewC removeAnnotations:existingpoints];
    NSString *urlMapString=[NSString stringWithFormat:@"http://www.logix.com/logix_webservice/map.php?format=json&truckno=%@",nam2];
    NSURL *urlMap=[NSURL URLWithString:urlMapString];
    NSData *dataMap=[NSData dataWithContentsOfURL:urlMap];
    NSError *errorMap;
    NSDictionary *jsonMap = [NSJSONSerialization JSONObjectWithData:dataMap options:kNilOptions error:&errorMap]; NSArray *resultsMap = [jsonMap valueForKey:@"posts"];
    NSArray *resMap = [resultsMap valueForKey:@"post"];
    NSArray *latitudeString=[resMap valueForKey:@"latitude"];
    NSString *latOrgstring = [latitudeString objectAtIndex:0];
    latitude=[latOrgstring doubleValue];
    NSArray *longitudeString=[resMap valueForKey:@"longitude"];
    NSString *longOrgstring = [longitudeString objectAtIndex:0];
    longitude=[longOrgstring doubleValue];
    NSString *ignation=[[resMap valueForKey:@"ignition"]objectAtIndex:0];
    //MAP VIEW Point
    MKCoordinateRegion myRegion;
    //Center
    CLLocationCoordinate2D center;
    center.latitude=latitude;
    center.longitude=longitude;
    //Span
    MKCoordinateSpan span;
    span.latitudeDelta=0.01f;
    span.longitudeDelta=0.01f;
    myRegion.center=center;
    myRegion.span=span;
    //Set our mapView
    [MapViewC setRegion:myRegion animated:YES];
    //Annotation
    //1.create coordinate for use with the annotation
    //CLLocationCoordinate2D wimbLocation;
    wimbLocation1.latitude=latitude;
    wimbLocation1.longitude=longitude;
    Annotation * myAnnotation= [Annotation alloc];
    CLLocation *someLocation=[[CLLocation alloc]initWithLatitude:latitude longitude:longitude];
    CLGeocoder *geocoder = [[CLGeocoder alloc] init];
    [geocoder reverseGeocodeLocation:someLocation completionHandler:^(NSArray *placemarks, NSError *error) {
        NSDictionary *dictionary = [[placemarks objectAtIndex:0] addressDictionary];
        addressOutlet=[dictionary valueForKey:@"Street"];
        City=[dictionary valueForKey:@"City"];
        State=[dictionary valueForKey:@"State"];
        myAnnotation.coordinate=wimbLocation1;
        if (addressOutlet!=NULL&&City!=NULL)
        {
            myAnnotation.title=addressOutlet;
            myAnnotation.subtitle=[NSString stringWithFormat:@"%@,%@", City, State];
        }
        [self.MapViewC addAnnotation:myAnnotation];
         [self line];
    }];
  }
  -(void)line
{
    CLLocationCoordinate2D coordinateArray[2];
    coordinateArray[0] = CLLocationCoordinate2DMake(latitude, longitude);
    coordinateArray[1] = CLLocationCoordinate2DMake(latitude, longitude);
    self.routeLine = [MKPolyline polylineWithCoordinates:coordinateArray count:2];
    [self.MapViewC addOverlay:self.routeLine];


}
-(MKOverlayView *)mapView:(MKMapView *)mapView viewForOverlay:(id<MKOverlay>)overlay
{
    if(overlay == self.routeLine)
    {
        if(nil == self.routeLineView)
        {
            self.routeLineView = [[MKPolylineView alloc] initWithPolyline:self.routeLine];
            self.routeLineView.fillColor = [UIColor redColor];
            self.routeLineView.strokeColor = [UIColor redColor];
            self.routeLineView.lineWidth = 5;
        }
        return self.routeLineView;
    }
    return nil;
}

请建议我纠正我的错误。提前谢谢...

Answer 1

试试这个....这会帮助你...

-(MKOverlayView *)mapView:(MKMapView *)mapView viewForOverlay:(id<MKOverlay>)overlay
{

        {
            self.routeLineView = [[MKPolylineView alloc] initWithPolyline:self.routeLine];
            self.routeLineView.strokeColor = [UIColor redColor];
            self.routeLineView.lineWidth = 5;
        }
        return self.routeLineView;
}