我如何知道 MKMapview setRegion:animated: 何时完成？

Question

我想在我的 MKMapView 上设置一个区域，然后找到与地图的东北角和西南角相对应的坐标。

This code works just fine to do that:
//Recenter and zoom map in on search location
MKCoordinateRegion region =  {{0.0f, 0.0f}, {0.0f, 0.0f}};
region.center = mySearchLocation.searchLocation.coordinate;
region.span.longitudeDelta = 0.01f;
region.span.latitudeDelta = 0.01f;
[self.mapView setRegion:region animated:NO]; //When this is set to YES it seems to break the coordinate calculation because the map is in motion

//After the new search location has been added to the map, and the map zoomed, we need to update the search bounds
//First we need to calculate the corners of the map so we get the points
CGPoint nePoint = CGPointMake(self.mapView.bounds.origin.x + mapView.bounds.size.width, mapView.bounds.origin.y);
CGPoint swPoint = CGPointMake((self.mapView.bounds.origin.x), (mapView.bounds.origin.y + mapView.bounds.size.height));

//Then transform those point into lat,lng values
CLLocationCoordinate2D neCoord;
neCoord = [mapView convertPoint:nePoint toCoordinateFromView:mapView];
CLLocation *neLocation = [[CLLocation alloc] initWithLatitude:neCoord.latitude longitude:neCoord.longitude];

CLLocationCoordinate2D swCoord;
swCoord = [mapView convertPoint:swPoint toCoordinateFromView:mapView];
CLLocation *swLocation = [[CLLocation alloc] initWithLatitude:swCoord.latitude longitude:swCoord.longitude];

问题是我希望地图缩放具有动画效果。但是，当我将 setRegion:animated 设置为 YES 时，我最终会在地图缩小时（即在动画完成之前）从地图中获取坐标。有什么方法可以得到动画完成的信号吗？

Answer 1

从未使用过mapkit，但MKMapViewDelegate 有一个方法 mapView:regionDidChangeAnimated: ，看起来就是您正在寻找的方法。

请注意，mapView:regionDidChangeAnimated: 每次发生变化时（例如当用户移动地图时）都会被调用。

Answer 2

我知道这已经很老了，但以防万一其他人来寻找答案，这里有一个替代方案。

这个版本的好处是，您可以在第一个动画完成时运行完成动画，而不是在回调方法中猜测/硬编码它，因为该动画是立即调用的。

[MKMapView animateWithDuration:1.0 animations:^{
    [mapView setRegion:mapRegion animated:YES];
} completion:^(BOOL finished) {
    [UIView animateWithDuration:1.0 animations:^{
        self.mapDotsImageView.alpha = 1.0;
    }];
}];

或者只是

// zoom in...
let km3:CLLocationDistance = 3000
let crTight = MKCoordinateRegionMakeWithDistance(location.coordinate, km3, km3)
MKMapView.animate(withDuration: 1.0, animations: { self.theMap.region = crTight })