iphone - How to add a push pin to a MKMapView(IOS) when touching?

Question

I had to get the coordinate of a point where the user touch on a MKMapView. I'm not working with the Interface Builder. Can you give me one example?

Answer 1

You can use a UILongPressGestureRecognizer for this. Wherever you create or initialize the mapview, first attach the recognizer to it:

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];

Then in the gesture handler:

- (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 is a class you define that conforms to the MKAnnotation protocol. If your app will only be running on iOS 4.0 or later, you can use the pre-defined MKPointAnnotation class instead.

For examples on creating your own MKAnnotation class, see the sample app MapCallouts.