我们在iOS7中使用MKMapView的地图区域遇到了一些问题。当我们的应用程序启动并且设备已经改变了UI方向几次后，map.region返回的值变得非常奇怪。它们往往具有合理的经度跨度，但纬度跨度较小，或者反之，就好像地图认为其边界已被削减为沿屏幕一侧的狭长矩形。即使在发生这种情况之后，MKMapView的实际边界和框架仍然是合理的。
通过从地图的实际边界计算出自己的区域，我们已经能够解决其中的一些问题，但我们仍然有一些无法解决的问题。例如，当点击注释以显示其标签时，地图有时会平移，将标签移动到它认为占据的屏幕小部分。
是否还有其他人遇到过这个问题？
如果有用的话，以下是我们实施解决方法的shims：
通过从地图的实际边界计算出自己的区域，我们已经能够解决其中的一些问题，但我们仍然有一些无法解决的问题。例如，当点击注释以显示其标签时，地图有时会平移，将标签移动到它认为占据的屏幕小部分。
是否还有其他人遇到过这个问题？
如果有用的话，以下是我们实施解决方法的shims：
+(void)setMap: (MKMapView*) map region:(MKCoordinateRegion) region
{
CGRect realBounds = map.bounds;
MKCoordinateRegion claimedRegion = map.region; // the map's claimed region, which is wonkily different after a rotate in ios7
CGRect claimedBounds = [map convertRegion:claimedRegion toRectToView:map]; // the bounds which the map thinks its region occupies
// if we want region to map to realBounds, but the map thinks it is only claimedBounds big, what
// reduced region will map to claimedBounds ?
MKCoordinateRegion reducedRegion = [Utilities sliceRegion: region inBounds: realBounds toReducedBounds: claimedBounds];
[map setRegion:reducedRegion animated:YES];
}
+ (MKCoordinateRegion) sliceRegion: (MKCoordinateRegion) bigRegion inBounds: (CGRect) wholeBounds toReducedBounds: (CGRect) reducedBounds
{
MKCoordinateRegion reducedRegion;
// Coords of our region's corners in lat/long
CLLocationDegrees left = bigRegion.center.longitude - bigRegion.span.longitudeDelta/2.0;
CLLocationDegrees right = bigRegion.center.longitude + bigRegion.span.longitudeDelta/2.0;
CLLocationDegrees top = bigRegion.center.latitude + bigRegion.span.latitudeDelta/2.0;
CLLocationDegrees bottom = bigRegion.center.latitude - bigRegion.span.latitudeDelta/2.0;
// Coords of our bounds in pixels
CGFloat wholeLeft = wholeBounds.origin.x;
CGFloat wholeRight = wholeBounds.origin.x + wholeBounds.size.width;
CGFloat wholeTop = wholeBounds.origin.y;
CGFloat wholeBottom = wholeBounds.origin.y + wholeBounds.size.height;
// Coords of the smaller bounds in pixels
CGFloat reducedLeft = reducedBounds.origin.x;
CGFloat reducedRight = reducedBounds.origin.x + reducedBounds.size.width;
CGFloat reducedTop = reducedBounds.origin.y;
CGFloat reducedBottom = reducedBounds.origin.y + reducedBounds.size.height;
// Now work out what the lat & long values for the corners of the reduced bounds are
CLLocationDegrees newLeft = left + (right-left) * (reducedLeft - wholeLeft) / (wholeRight - wholeLeft);
CLLocationDegrees newRight = left + (right-left) * (reducedRight - wholeLeft) / (wholeRight - wholeLeft);
CLLocationDegrees newTop = top + (bottom - top) * (reducedTop - wholeTop) / (wholeBottom - wholeTop);
CLLocationDegrees newBottom = top + (bottom - top) * (reducedBottom - wholeTop) / (wholeBottom - wholeTop);
reducedRegion.center.longitude = (newRight + newLeft) / 2.0;
reducedRegion.center.latitude = (newBottom + newTop) / 2.0;
reducedRegion.span.longitudeDelta = newRight - newLeft;
reducedRegion.span.latitudeDelta = newTop - newBottom;
return reducedRegion;
}
+(MKCoordinateRegion)getMapRegion: (MKMapView*) map
{
CGRect bounds = map.bounds;
MKCoordinateRegion region = [map convertRect:bounds toRegionFromView:map]; // the region we can see on the screen, not the map's wonky region!
if ((region.span.latitudeDelta < 0.0) || (region.span.longitudeDelta < 0.0) || region.span.longitudeDelta / region.span.latitudeDelta > 5.0 || region.span.latitudeDelta / region.span.longitudeDelta > 5.0 )
{
LogD(@"getMap: region: bad span - lat: %f, long: %f", region.span.latitudeDelta, region.span.longitudeDelta);
}
return region;
}
+(void)setMap: (MKMapView*) map center: (CLLocationCoordinate2D) center
{
CGRect bounds = map.bounds;
MKCoordinateRegion boundsRegion = [map convertRect:bounds toRegionFromView:map]; // the region we can see on the screen
MKCoordinateRegion claimedRegion = map.region; // the map's claimed region, which is wonkily different after a rotate in ios7
CLLocationCoordinate2D offsetCenter; // make up a value to tell the map to center on which will make it really center
offsetCenter.latitude = center.latitude - ( boundsRegion.center.latitude - claimedRegion.center.latitude );
offsetCenter.longitude = center.longitude - ( boundsRegion.center.longitude - claimedRegion.center.longitude );
[map setCenterCoordinate:offsetCenter animated:YES];
}
+(CLLocationCoordinate2D)getMapCenter: (MKMapView*) map
{
CGRect bounds = map.bounds;
MKCoordinateRegion boundsRegion = [map convertRect:bounds toRegionFromView:map]; // the region we can see on the screen
return boundsRegion.center;
}