Question

我尝试使用segue上的注释标题更新下一个视图中的标签，我不知道该怎么做，但正在研究这个问题。任何建议或是否需要在创建注释的地方完成？

- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender
{
    if ([[segue identifier] isEqualToString:@"pushShare"])
    {
        ShareViewController *vc = (ShareViewController *)segue.destinationViewController;
        [vc fromLabel.text = StartAnnotation.title];
    }
}

更新单击按钮时会创建注释，在用户位置放置引脚并且注释标题显示地址，Iv尝试使用标题在同一视图中更新标签但是也遇到问题。

用于创建注释的代码

CLLocationCoordinate2D theCoordinate = {_map.userLocation.location.coordinate.latitude,_map.userLocation.location.coordinate.longitude};
CLLocation *currentLocation = [[CLLocation alloc]
                               initWithLatitude:_map.userLocation.location.coordinate.latitude
                               longitude:_map.userLocation.location.coordinate.longitude];

NSLog(@"self.geocoder=%@", self.geocoder);
[self.geocoder reverseGeocodeLocation:currentLocation completionHandler:^(NSArray *placemark, NSError *error) {

    NSString *address = @"Address unknown";
    NSLog(@"geocoder error=%@", error);

    if (placemark.count > 0)
    {
        CLPlacemark *topResult = [placemark objectAtIndex:0];
        address = [NSString stringWithFormat:@"%@ %@ %@ %@", topResult.subThoroughfare, topResult.thoroughfare, topResult.subLocality, topResult.locality];
    }
StartAnnotation *startPoint = [[StartAnnotation alloc]init];
startPoint.coordinate = theCoordinate;
startPoint.title = address;
startPoint.subtitle = @"Start Point";

[self.map addAnnotation:startPoint];
[self.map selectAnnotation:startPoint animated:YES];
}];
//e.g. fromLabel.text = StartAnnotation.title;

Answer 1

您可以使用 didSelectAnnotationView 来检测用户何时点击 MKAnnotationView ，如下例所示：

- (void)mapView:(MKMapView *)mapView didSelectAnnotationView:(MKAnnotationView *)view
{
    [mapView deselectAnnotation:view.annotation animated:YES];

    [self performSegueWithIdentifier:YOUR_SEGUE_ID
                              sender:view];
}

然后在 prepareForSegue 中提取注释的标题并使用它：

- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender
{
    if ([[segue identifier] isEqualToString:YOUR_SEGUE_ID])
    {
        UIView *annotationView = (UIView *)sender;

        ShareViewController *vc = (ShareViewController *)segue.destinationViewController;
        vc.textToSetOnTheLabel = annotationView.annotation.title;
    }
}

从注释标题更新标签文本

1 个答案: