我们在 iOS7 中遇到了 MKMapView 区域的问题。
在我们的应用程序启动并且设备改变了几次 UI 方向之后,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,反之亦然,就好像地图给人的印象是其边界已沿屏幕的一个边缘缩小为一个狭窄的矩形。发生这种情况后,MKMapView 的实际边界和框架仍然是合理的。
通过根据地图的实际边界计算我们自己的区域,可以解决由此引起的一些问题,但我们仍然有一些问题无法解决。例如,当点击注释以显示其标注时,地图有时会平移以将标注移动到它认为它占据的屏幕的一小部分。
有没有其他人遇到过这个问题?
我们实施解决方法的垫片如下,以防它们有用:
+(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;
}