How do I determine if a coordinate is in the currently visible map region?

Question

I have a list of several hundred locations and only want to display an MKPinAnnotation for those locations currently on the screen. The screen starts with the user\'s curren

Answer 1

In your code, you should pass a view for the toPointToView: option. I gave it my mapView. You have to specify an upper bound for the x and y too.

Here's some code which worked for me (told me the currently visible annotations on my map, while looping through the annotation):

for (Shop *shop in self.shops) {
    ShopAnnotation *ann = [ShopAnnotation annotationWithShop:shop];
    [self.mapView addAnnotation:ann];

    CGPoint annPoint = [self.mapView convertCoordinate:ann.coordinate 
            toPointToView:self.mapView];

    if (annPoint.x > 0.0 && annPoint.y > 0.0 && 
            annPoint.x < self.mapView.frame.size.width && 
            annPoint.y < self.mapView.frame.size.height) {
        NSLog(@"%@ Coordinate: %f %f", ann.title, annPoint.x, annPoint.y);
    }
}