why it show last pin's type of call out annotation in my mapview

I am designing a map view in which i am dropping no. of pins. I have also add a custom view on every pin. Now problem is that when my map view add all pins then on map it don't show my last pin. Instead of last pin it will show only custom view which is not hidden when i tap on that. And on some pins it not add custom view. I am showing my code below... class.h

@interface MappingBusinesses : UIViewController {

MKMapView *_mapView;
CalloutMapAnnotation *_calloutAnnotation;
MKAnnotationView *_selectedAnnotationView;
Places *Place_Object;
DisplayMap *dm;
NSMutableArray *routepoints;
CSMapRouteLayerView *routeView;
UICRouteOverlayMapView *routeOverlayView;
UICGDirections *diretions;
Yelp_OnTheWayAppDelegate *appDelegate;
NSArray *wayPoints;
UICGTravelModes travelMode;
DetailView *DV_Object;
UIActivityIndicatorView *aiv;
UILabel *label;
UIView *prosView;
BusinessData *bd_object;

}

class.m

 - (void)viewDidLoad {
[super viewDidLoad];

 appDelegate = (Yelp_OnTheWayAppDelegate *)[[UIApplication sharedApplication] delegate];
self.title=@"Map";
//[NSThread detachNewThreadSelector:@selector(start) toTarget:self withObject:nil];
label.text=[NSString stringWithFormat:@"%d places along your route",[appDelegate.busines_Aray count]];
[self.mapView setMapType:MKMapTypeStandard];
[self.mapView setZoomEnabled:YES];
[self.mapView setScrollEnabled:YES];
[self.mapView setDelegate:self];
MKCoordinateRegion region = { {0.0, 0.0 }, { 0.0, 0.0 } };
region.center.latitude = appDelegate.start_lat;
region.center.longitude = appDelegate.start_long;
region.span.longitudeDelta = 0.01f;
region.span.latitudeDelta = 0.01f;  
[self.mapView setRegion:region animated:YES];

dm=[[DisplayMap alloc]init];
for(int i=0;i<[appDelegate.mapPin_aray count];i++)
{
    CLLocationCoordinate2D coord; 
    coord.latitude=[[appDelegate.mapPin_lat objectAtIndex:i] floatValue];
    coord.longitude=[[appDelegate.mapPin_long objectAtIndex:i] floatValue];
    self.calloutAnnotation = [[CalloutMapAnnotation alloc] initWithLatitude:coord.latitude andLongitude:coord.longitude] ;
    [self.mapView addAnnotation:self.calloutAnnotation];
    NSLog(@"coordinate of number%i is %f and %f",i,coord.latitude,coord.longitude);

    }

}

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

if ([annotation isKindOfClass:[MKUserLocation class]]) {
    return nil;     
}
static NSString *identifier = @"RoutePinAnnotation";
if ([annotation isKindOfClass:[UICRouteAnnotation class]]) {
    MKPinAnnotationView *pinAnnotation = (MKPinAnnotationView *)[self.mapView dequeueReusableAnnotationViewWithIdentifier:identifier];
    if(!pinAnnotation) {
        pinAnnotation = [[[MKPinAnnotationView alloc] initWithAnnotation:annotation reuseIdentifier:identifier] autorelease];
    }

    if ([(UICRouteAnnotation *)annotation annotationType] == UICRouteAnnotationTypeStart) {
        pinAnnotation.pinColor = MKPinAnnotationColorGreen;
    } else if ([(UICRouteAnnotation *)annotation annotationType] == UICRouteAnnotationTypeEnd) {
        pinAnnotation.pinColor = MKPinAnnotationColorPurple;
    } else {
        pinAnnotation.pinColor = MKPinAnnotationColorPurple;
    }

    pinAnnotation.animatesDrop = YES;
    pinAnnotation.enabled = YES;
    pinAnnotation.canShowCallout = YES;
    return pinAnnotation;
} 

static NSString * const kPinAnnotationIdentifier = @"PinIdentifier";
 if (annotation == self.calloutAnnotation) {
    CalloutMapAnnotationView *calloutMapAnnotationView = (CalloutMapAnnotationView *)[self.mapView dequeueReusableAnnotationViewWithIdentifier:kPinAnnotationIdentifier];
    if (!calloutMapAnnotationView) {
        calloutMapAnnotationView = [[[CalloutMapAnnotationView alloc] initWithAnnotation:annotation 
                                                                         reuseIdentifier:@"CalloutAnnotation"] autorelease];
        calloutMapAnnotationView.contentHeight = 70.0f;
        bd_object=[appDelegate.busines_Aray objectAtIndex:self.calloutAnnotation.pinID];
        UITextField *txtname=[[UITextField alloc] initWithFrame:CGRectMake(0, 5, 150, 30)];
        txtname.text=[NSString stringWithFormat:@"%@",bd_object.name_business ];
        txtname.userInteractionEnabled=NO;
        txtname.font = [UIFont boldSystemFontOfSize:18];
        txtname.font=[UIFont fontWithName:@"Arial" size:18];
        txtname.textColor = [UIColor whiteColor];
        txtname.opaque = false;
        txtname.backgroundColor = [UIColor clearColor];
        [calloutMapAnnotationView.contentView addSubview:txtname];
        [txtname release];

        UILabel *gpsCoordinatesLabel = [[UILabel alloc] initWithFrame:CGRectMake(0, 40, 70, 20)];
        gpsCoordinatesLabel.text = @"Categories:";
        gpsCoordinatesLabel.font = [UIFont boldSystemFontOfSize:14];
      gpsCoordinatesLabel.font=[UIFont fontWithName:@"Arial" size:14];
        gpsCoordinatesLabel.textColor = [UIColor whiteColor];
        gpsCoordinatesLabel.opaque = false;
        gpsCoordinatesLabel.backgroundColor = [UIColor clearColor];
        gpsCoordinatesLabel.textAlignment = UITextAlignmentRight;
        [calloutMapAnnotationView.contentView addSubview:gpsCoordinatesLabel];
        [gpsCoordinatesLabel release];

        UITextField *txtcate=[[UITextField alloc] initWithFrame:CGRectMake(70, 40, 100, 30)];
开发者_运维问答        txtcate.text=[NSString stringWithFormat:@"%@", bd_object.cat_business];
        txtcate.userInteractionEnabled=NO;
        txtcate.font = [UIFont boldSystemFontOfSize:18];
        txtcate.font=[UIFont fontWithName:@"Arial" size:18];
        txtcate.textColor = [UIColor whiteColor];
        txtcate.opaque = false;
        txtcate.backgroundColor = [UIColor clearColor];
        [calloutMapAnnotationView.contentView addSubview:txtcate];
        [txtcate release];

        UITextField *txtReview=[[UITextField alloc] initWithFrame:CGRectMake(190, 40, 40, 30)];
        txtReview.text=[NSString stringWithFormat:@"%d", bd_object.noofreview];
        txtReview.userInteractionEnabled=NO;
        txtReview.font = [UIFont boldSystemFontOfSize:18];
        txtReview.textColor = [UIColor whiteColor];
        txtReview.opaque = false;
        txtReview.backgroundColor = [UIColor clearColor];
        [calloutMapAnnotationView.contentView addSubview:txtReview];
        [txtReview release];

        UIImageView *imgView=[[UIImageView alloc] initWithFrame:CGRectMake(210, 40, 31, 23)];
        [imgView setImage:[UIImage imageNamed:@"reviewwhite.png"]];
        [calloutMapAnnotationView.contentView addSubview:imgView];
        [imgView release];


    }
    calloutMapAnnotationView.parentAnnotationView = self.selectedAnnotationView;
    calloutMapAnnotationView.mapView = self.mapView;

    return calloutMapAnnotationView;
} 

else {
    MKPinAnnotationView *annotationView = [[[MKPinAnnotationView alloc] initWithAnnotation:annotation 
                                                                           reuseIdentifier:@"CustomAnnotation"] autorelease];
    annotationView.canShowCallout = NO;
    annotationView.pinColor = MKPinAnnotationColorRed;
    return annotationView;
} 

MKAnnotationView *av;
return av;

}

- (void)mapView:(MKMapView *)mapView didSelectAnnotationView:(MKAnnotationView *)view {
if (self.calloutAnnotation != nil) {
    self.calloutAnnotation = [[CalloutMapAnnotation alloc] initWithLatitude:view.annotation.coordinate.latitude andLongitude:view.annotation.coordinate.longitude];
} else {
    self.calloutAnnotation.latitude = view.annotation.coordinate.latitude;
    self.calloutAnnotation.longitude = view.annotation.coordinate.longitude;
}

[self.mapView addAnnotation:self.calloutAnnotation];
self.selectedAnnotationView = view;

}

 - (void)mapView:(MKMapView *)mapView didDeselectAnnotationView:(MKAnnotationView *)view {
if (self.calloutAnnotation != nil) {
    [self.mapView removeAnnotation: self.calloutAnnotation];
}

}

Not sure, but I think the issue might be that during your initial loop in viewDidLoad, you're remembering the annotations in self.calloutAnnotation and then checking for it in didSelect and didDeselect.

The problem is that self.calloutAnnotation will be replaced every time round the init loop, so at the end, it will only be referencing the last annotation added. For example, when user selects a different annotation, you change self.calloutAnnotation's lat/long and add it again, but that will change the lat/long of the last annotation added in the array.