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目前我可以在地图周围放置图钉。现在我希望注释标题显示引脚放置的地址。

我看过这个但不能让我的工作：
将注释的标题设置为当前地址

我的 ViewController.m 中的代码

更新。

- (void)addPinToMap:(UIGestureRecognizer *)gestureRecognizer
{
    if (gestureRecognizer.state != UIGestureRecognizerStateBegan)
        return;

    CGPoint touchPoint = [gestureRecognizer locationInView:self.map];
    CLLocationCoordinate2D touchMapCoordinate =
    [self.map convertPoint:touchPoint toCoordinateFromView:self.map];

    CLLocation *currentLocation = [[CLLocation alloc]
                                   initWithLatitude:touchMapCoordinate.latitude
                                   longitude:touchMapCoordinate.longitude];

    [self.geocoder reverseGeocodeLocation:currentLocation completionHandler:^(NSArray *placemark, NSError *error) {

        //initialize the title to "unknown" in case geocode has failed...
        NSString *annTitle = @"Address unknown";

        //set the title if we got any placemarks...
        if (placemark.count > 0)
        {
            CLPlacemark *topResult = [placemark objectAtIndex:0];
            annTitle = [NSString stringWithFormat:@"%@ %@ %@ %@", topResult.country, topResult.locality, topResult.subLocality, topResult.thoroughfare];
        }

        //now create the annotation...
        MapAnnotation *toAdd = [[MapAnnotation alloc]init];

        toAdd.coordinate = touchMapCoordinate;
        toAdd.title = annTitle;
        //toAdd.title = @"Title";
        toAdd.subtitle = @"Subtitle";

        [self.map addAnnotation:toAdd];
    }];
}
4

1 回答 1

2

首先，在addPinToMap:方法中，addressLocation被调用currentLocation但currentLocation从未设置。它被声明了几行，但没有设置为任何值。

所以改变：

CLLocation *currentLocation;

到：

CLLocation *currentLocation = [[CLLocation alloc] 
                                initWithLatitude:touchMapCoordinate.latitude 
                                longitude:touchMapCoordinate.longitude];


其次，即使使用此修复程序，它仍然无法正常工作。注释title不会被设置，因为reverseGeocodeLocation方法的完成处理程序块将在注释已添加后完成（该块是异步的 - 中的代码addPinToMap:不会等待它完成）。

当您实际拥有地理编码器结果（无论是成功还是失败）时，您需要稍微更改代码并在完成块内添加注释。

将reverseGeocodeLocation调用移至addPinToMap:方法：

CLLocation *currentLocation = [[CLLocation alloc] 
                                initWithLatitude:touchMapCoordinate.latitude 
                                longitude:touchMapCoordinate.longitude];

[self.geocoder reverseGeocodeLocation:currentLocation completionHandler:^(NSArray *placemark, NSError *error) {

    //initialize the title to "unknown" in case geocode has failed...
    NSString *annTitle = @"Address unknown";

    //set the title if we got any placemarks...
    if (placemark.count > 0)
    {
        CLPlacemark *topResult = [placemark objectAtIndex:0];
        annTitle = [NSString stringWithFormat:@"%@ %@ %@ %@", topResult.country, topResult.locality, topResult.subLocality, topResult.thoroughfare];
    }

    //now create the annotation...
    MapAnnotation *toAdd = [[MapAnnotation alloc]init];

    toAdd.coordinate = touchMapCoordinate;
    toAdd.title = annTitle;
    toAdd.subtitle = @"Subtitle";

    [self.map addAnnotation:toAdd];
}];
于 2013-12-18T00:22:00.007 回答