iphone - map View 删除多个图钉

Question

我想在 map 上显示用户位置并放置一个图钉，但我的应用程序放置了两个相距一定距离的图钉。我想知道当新图钉被放置时如何删除旧图钉，以便应该有一个图钉 map 我的代码是:

-(MKAnnotationView *)mapView:(MKMapView *)mV viewForAnnotation:
(id <MKAnnotation>)annotation {

    MKPinAnnotationView *pinView = nil; 


    if(annotation != mapView.userLocation) 
    {



        static NSString *defaultPinID = @"com.invasivecode.pin";
        pinView = (MKPinAnnotationView *)[mapView dequeueReusableAnnotationViewWithIdentifier:defaultPinID];
        if ( pinView == nil ) pinView = [[[MKPinAnnotationView alloc]
                                          initWithAnnotation:annotation reuseIdentifier:defaultPinID] autorelease];



        pinView.pinColor = MKPinAnnotationColorGreen; 
        pinView.canShowCallout = YES;
        pinView.animatesDrop = YES;


        UILabel *label =[[UILabel alloc] initWithFrame:CGRectMake(0, -200, 300, 37)];

        [label setNumberOfLines:4];


        [label setFont:[UIFont boldSystemFontOfSize:10]];

        [label setText:[address objectAtIndex:0]];



        SportUpAppDelegate *appDelegate =[[UIApplication sharedApplication]delegate];



        appDelegate.currentLocation=[address objectAtIndex:0];


        [label setTextAlignment:UITextAlignmentLeft];
        [label setBackgroundColor:[UIColor clearColor]];
        [label setTextColor:[UIColor whiteColor]];


        [pinView setLeftCalloutAccessoryView:label];
        [label release];




    } 
    else {
        [mapView.userLocation setTitle:@"I am here"];
    }
    return pinView;
}

Answer 1

当删除旧引脚的注释时，您使用新的引脚使用此功能

[mapView removeAnnotations:mapView.annotations]; 
[mapView removeFromSuperview];

从 super View 中删除后调用加载 map ....再次使用

[self.view addSubview:mapView];

其中mapView是mapView的名称