Objective c 如何对注释进行反向地理编码？

我有一个应用程序可以删除多个注释，我想对pin位置进行反向地理编码，并将地址设置为字幕。这是我到目前为止的代码，但我不知道如何实现反向地理编码器

-(void)press:(UILongPressGestureRecognizer *)recognizer
{
    CGPoint touchPoint = [recognizer locationInView:worldView];
    CLLocationCoordinate2D touchMapCoordinate = [worldView convertPoint:touchPoint toCoordinateFromView:worldView];

    if (UIGestureRecognizerStateBegan == [recognizer state]) {
        MapPoint *mp = [[MapPoint alloc]initWithCoordinate:touchMapCoordinate
                                                 title:@"Dream House"];
        [worldView addAnnotation:mp];

        geocoder = [[CLGeocoder alloc]init];

        CLLocation *location = [[CLLocation alloc]initWithCoordinate:touchMapCoordinate
                                                        altitude:CLLocationDistanceMax
                                              horizontalAccuracy:kCLLocationAccuracyBest
                                                verticalAccuracy:kCLLocationAccuracyBest
                                                       timestamp:[NSDate date]];

        [geocoder reverseGeocodeLocation:location
                   completionHandler:^(NSArray *placemarks, NSError *error) {
                       <#code#>
                   }];

    }
}

-（void）按：（ui长按gesturecognizer*）识别器
{
CGPoint接触点=[识别器位置视图：worldView]；
CLLocationCoordinate2D touchMapCoordinate=[worldView convertPoint:touchPoint to CoordinateFromView:worldView]；
如果（UIgestureRecognitizerStateStart==[识别器状态]）{
MapPoint*mp=[[MapPoint alloc]initWithCoordinate:touchMapCoordinate
标题：@“梦想之家”]；
[worldView addAnnotation:mp]；
地理编码器=[[CLGeocoder alloc]init]；
CLLocation*location=[[CLLocation alloc]initWithCoordinate:touchMapCoordinate
海拔高度：CLLocationDistanceMax
水平精度：KCLLOCATIONACURACYBEST
垂直精度：KCLLOCATIONACURACYBEST
时间戳：[NSDate]]；
[地理编码器反转地理位置：位置]
completionHandler:^（NSArray*放置标记，NSError*错误）{
}];
}
}

别针会掉在房子上，所以我只想显示房子的地址。谢谢你的帮助