iOS地图的大头针的标题和子标题自动显示

- (void)createAnnotationWithCoords:(CLLocationCoordinate2D)coords

{   

    CustomAnnotation *annotation = [[CustomAnnotation alloc] initWithCoordinate:coords];//创建一个大头针对象，此类定义时必需满足MKAnnotation协议

    annotation.title = @"标题";//设置大头针的主标题
    annotation.subtitle = @"子标题";//设置大头针的负标题

   

    [self.map selectAnnotation:annotation animated:YES];//标题和子标题自动显示
    
    
    [self.map addAnnotation: annotation];//把大头针加到地图上

    [annotation release];

}