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

    //由于当前位置的标注也是一个大头针，所以此时需要判断，此代理方法返回nil使用默认大头针视图

    if ([annotation isKindOfClass:[NearBrandAnnotation class]]) {

        static NSString *key1=@"NearBrandAnnotation";

        annotationView=[mapView dequeueReusableAnnotationViewWithIdentifier:key1];

        //如果缓存池中不存在则新建

        if (!annotationView) {

            annotationView=[[MKAnnotationView alloc]initWithAnnotation:annotation reuseIdentifier:key1];

            annotationView.canShowCallout=YES;//允许交互点击

            annotationView.calloutOffset=CGPointMake(, );//定义详情视图偏移量

            UIButton * btn = [[UIButton alloc]initWithFrame:CGRectMake(, , , )];

            btn.backgroundColor = BLUECOLOR;

            [btn setTitle:@"到这去" forState:UIControlStateNormal];

            [btn addTarget:self action:@selector(turnAction:) forControlEvents:UIControlEventTouchUpInside];

            annotationView.rightCalloutAccessoryView=btn;//定义详情左侧视图

            //注意：初始化必须设置为NO,否则会出现大片大头针默认展开副标题问题

            annotationView.selected = NO;

           objc_setAssociatedObject(btn, @"annotation",annotation, OBJC_ASSOCIATION_RETAIN_NONATOMIC);

        }

        //修改大头针视图

        //重新设置此类大头针视图的大头针模型(因为有可能是从缓存池中取出来的，位置是放到缓存池时的位置)

        annotationView.annotation=annotation;

        annotationView.image=[UIImage imageNamed:@"brandPin"];//设置大头针视图的图片

        return annotationView;

    }else {

        return nil;

    }

}

- (void)setMapRegion{

    if (_strLatitude&&_strLongitude&&mapView) {

        int distance;

        if ([_distance intValue] == 0) {

            distance = 1000*25;

        }else{

            distance = 1000*[_distance intValue];

        }

        CLLocationCoordinate2D coords = CLLocationCoordinate2DMake(_strLatitude,_strLongitude);//纬度，经度

        [mapView setRegion:MKCoordinateRegionMakeWithDistance(coords, distance, distance) animated:YES];

    }

}