在缩放时防止在MKMapView中滚动

- (BOOL)canScroll {
    return YES;
}

- (void)setScrollEnabled:(BOOL)enabled {
    _scrollEnabled = enabled;
    [self update];
}

- (CGFloat)zoomScale {
    CGFloat zoomScale = self.minZoom;
    if (self.zoomLevel > 1) {
        zoomScale = self.maxZoom;
    }
    return zoomScale;
}

- (UIView *)viewForZoomingInMapView:(MKMapView *)mapView {
    // ...
}

- (void)update {
    MKMapRect bounds = self.visibleMapRect;
    MKMapPoint northWest = MKMapPointMake(bounds.origin.x, bounds.size.height);
    MKMapPoint southEast = MKMapPointMake(bounds.origin.x + bounds.size.width, bounds.size.height);
    MKMapRect visibleRect = MKMapRectMake(northWest.x, southEast.y, northWest.x - southEast.x, southEast.y - northWest.y);
    
    [self setRegion:visibleRect];
}