iphone - 触摸时如何向 MKMapView(IOS) 添加图钉？

Question

我必须获取用户在 MKMapView 上触摸的点的坐标。我没有使用 Interface Builder。你能给我一个例子吗？

Answer 1

您可以为此使用UILongPressGestureRecognizer。无论您在哪里创建或初始化地图视图，首先将识别器附加到它：

UILongPressGestureRecognizer *lpgr = [[UILongPressGestureRecognizer alloc] 
    initWithTarget:self action:@selector(handleLongPress:)];
lpgr.minimumPressDuration = 2.0; //user needs to press for 2 seconds
[self.mapView addGestureRecognizer:lpgr];
[lpgr release];

然后在手势处理程序中：

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

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

    YourMKAnnotationClass *annot = [[YourMKAnnotationClass alloc] init];
    annot.coordinate = touchMapCoordinate;
    [self.mapView addAnnotation:annot];
    [annot release];
}

YourMKAnnotationClass 是您定义的符合MKAnnotation协议的类。如果您的应用程序仅在 iOS 4.0 或更高版本上运行，您可以改用预定义的MKPointAnnotation类。

有关创建您自己的 MKAnnotation 类的示例，请参阅示例应用程序MapCallouts。

Answer 2

感谢 Anna 提供了这么好的答案！如果有人感兴趣，这里是一个 Swift 版本（答案已更新为 Swift 4.1 语法）。

创建 UILongPressGestureRecognizer：

let longPressRecogniser = UILongPressGestureRecognizer(target: self, action: #selector(MapViewController.handleLongPress(_:)))
longPressRecogniser.minimumPressDuration = 1.0
mapView.addGestureRecognizer(longPressRecogniser)

处理手势：

@objc func handleLongPress(_ gestureRecognizer : UIGestureRecognizer){
    if gestureRecognizer.state != .began { return }

    let touchPoint = gestureRecognizer.location(in: mapView)
    let touchMapCoordinate = mapView.convert(touchPoint, toCoordinateFrom: mapView)

    let album = Album(coordinate: touchMapCoordinate, context: sharedContext)

    mapView.addAnnotation(album)
}