show multiple annotation in map view

问题

i am new to map view in ios sdk. i want to show multiple annotation in map view using lat and long.basically all lat and long are coming from server side in json format. i am parsing all lat and long and saving it in different array. but how to show all annotation at single time. i am able to show only one annotation at a time.Below is code for single annotation i am using,

zoomLocation.latitude = latmpa.doubleValue;
zoomLocation.longitude = logmpa.doubleValue;
annotationPoint = [[MKPointAnnotation alloc] init];
annotationPoint.coordinate = zoomLocation;
annotationPoint.title = @"masjid....";
[mapView selectAnnotation:annotationPoint animated:YES];


[mapView addAnnotation:annotationPoint];

mapView.centerCoordinate = annotationPoint.coordinate;

MKCoordinateSpan span;
span.latitudeDelta = 1.5;
span.longitudeDelta = 1.0;
MKCoordinateRegion newRegion;
newRegion.center = zoomLocation;
newRegion.span = span;
[mapView setRegion:newRegion animated:YES];

回答1:

Try This

for ( int i=0; i<[yourLatLongarray count]; i++)
{
CLLocationCoordinate2D coord;

    coord.latitude=[[NSString stringWithFormat:@"%@",[yourLatitudeArray objectAtIndex:i]] floatValue];
    coord.longitude=[[NSString stringWithFormat:@"%@",
                      [yourLongitudeArray objectAtIndex:i]] floatValue];
    MKCoordinateRegion region1;
    region1.center=coord;
    region1.span.longitudeDelta=20 ;
    region1.span.latitudeDelta=20;
    [mapview setRegion:region1 animated:YES];

    NSString *titleStr =[namesArr objectAtIndex:i] ;
   // NSLog(@"title is:%@",titleStr);

  MyAnnotation*  annotObj =[[MyAnnotation alloc]initWithCoordinate:coord title:titleStr];
    [mapview addAnnotation:annotObj];

}

MyAnnotation.h is

@interface MyAnnotation : NSObject <MKAnnotation>
{   
   CLLocationCoordinate2D coordinate;
   NSString *title;
   NSString *subTitle;
   NSString *time;
}

@property (nonatomic)CLLocationCoordinate2D coordinate;

@property (nonatomic, retain) NSString *title;

@property (nonatomic, retain) NSString *subTitle;

@property (nonatomic,retain) NSString *time;

-(id)initWithCoordinate:(CLLocationCoordinate2D) c  title:(NSString *) t  subTitle:(NSString *)timed time:(NSString *)tim;

-(id)initWithCoordinate:(CLLocationCoordinate2D) c title:(NSString *)tit;

@end

MyAnnotation.m is

@implementation MyAnnotation

@synthesize coordinate;

@synthesize title;

@synthesize time;

@synthesize subTitle;

-(id)initWithCoordinate:(CLLocationCoordinate2D) c  title:(NSString *) t  subTitle:(NSString *)timed time:(NSString *)tim
{
   self.coordinate=c;
   self.time=tim;
   self.subTitle=timed;
   self.title=t;
   return self;
}

-(id)initWithCoordinate:(CLLocationCoordinate2D) c title:(NSString *)tit
{
    self.coordinate=c;
    self.title=tit;
    return self;
}

@end

回答2:

Get all the latitudes and longitudes in array and go for the for loop as user1673099 said,

and add the following zoomtofit code for zooming the mapview to cover all the annotations in the mapview by calling the method,

[self zoomToFitMapAnnotations:self.mapView];

- (void)zoomToFitMapAnnotations:(MKMapView *)mapView {
if ([mapView.annotations count] == 0) return;

CLLocationCoordinate2D topLeftCoord;
topLeftCoord.latitude = -90;
topLeftCoord.longitude = 180;
CLLocationCoordinate2D bottomRightCoord;
bottomRightCoord.latitude = 90;
bottomRightCoord.longitude = -180;

for(id<MKAnnotation> annotation in mapView.annotations) {
    topLeftCoord.longitude = fmin(topLeftCoord.longitude, annotation.coordinate.longitude);
    topLeftCoord.latitude = fmax(topLeftCoord.latitude, annotation.coordinate.latitude);
    bottomRightCoord.longitude = fmax(bottomRightCoord.longitude, annotation.coordinate.longitude);
    bottomRightCoord.latitude = fmin(bottomRightCoord.latitude, annotation.coordinate.latitude);
}

MKCoordinateRegion region;
region.center.latitude = topLeftCoord.latitude - (topLeftCoord.latitude - bottomRightCoord.latitude) * 0.5;
region.center.longitude = topLeftCoord.longitude + (bottomRightCoord.longitude - topLeftCoord.longitude) * 0.5;
region.span.latitudeDelta = fabs(topLeftCoord.latitude - bottomRightCoord.latitude) * 1.1;

region.span.longitudeDelta = fabs(bottomRightCoord.longitude - topLeftCoord.longitude) * 1.1;

region = [mapView regionThatFits:region];
[mapView setRegion:region animated:YES];
}

来源：https://stackoverflow.com/questions/19627740/show-multiple-annotation-in-map-view