Question

Hai是xcode的新手我正在使用mkmap开发一个用于车辆跟踪的iOS应用程序我需要根据车辆移动每5秒在注释之间绘制线条，我的问题是它是第一次仅绘制线条而是从第二个刷新间隔它不起作用，我的代码在下面，

- (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;
}

请建议我纠正错误。提前谢谢......

Answer 1

试试这个......这会对你有帮助......

-(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;
}

如何在x个移动注释之间画线？

1 个答案: