iOS7 的 Windows 与 iOS8/9 的 Windows 有不同的行为。
iOS7 的键盘窗口和 iOS8/9 的所有窗口始终具有正确的方向和大小。因此，您可以观察大小更改事件并更新视图的框架。
但iOS7的其他窗口始终保持纵向和大小。旋转后您需要更新视图的变换。
您需要像这样观察 UIApplicationWillChangeStatusBarOrientationNotification 并更新 UIView 的大小：
@interface MyView : UIView
@end
@implementation MyView
- (instancetype)init
{
if (self = [super init]) {
[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(changeOrientationHandler:) name:UIApplicationWillChangeStatusBarOrientationNotification object:nil];
}
return self;
}
- (void)dealloc
{
[[NSNotificationCenter defaultCenter] removeObserver:self name:UIApplicationWillChangeStatusBarOrientationNotification object:nil];
}
- (void)updateTransformWithOrientation:(UIInterfaceOrientation)orientation
{
CGFloat width = CGRectGetWidth(self.window.bounds);
CGFloat height = CGRectGetHeight(self.window.bounds);
if (width > height) {
CGFloat temp = width;
width = height;
height = temp;
}
CGFloat offset = (height - width) / 2;
CGAffineTransform transform;
switch (orientation) {
case UIInterfaceOrientationLandscapeLeft:
transform = CGAffineTransformMakeTranslation(-offset, offset);
transform = CGAffineTransformRotate(transform, -M_PI_2);
break;
case UIInterfaceOrientationLandscapeRight:
transform = CGAffineTransformMakeTranslation(-offset, offset);
transform = CGAffineTransformRotate(transform, M_PI_2);
break;
case UIInterfaceOrientationPortraitUpsideDown:
transform = CGAffineTransformMakeRotation(-M_PI);
break;
default:
transform = CGAffineTransformIdentity;
break;
}
self.transform = transform;
self.frame = CGRectMake(0, 0, width, height);
}
- (void)updateFrameWithOrientation:(UIInterfaceOrientation)orientation
{
CGFloat width = CGRectGetWidth(self.window.bounds);
CGFloat height = CGRectGetHeight(self.window.bounds);
if (width > height) {
CGFloat temp = width;
width = height;
height = temp;
}
switch (orientation) {
case UIInterfaceOrientationLandscapeLeft:
case UIInterfaceOrientationLandscapeRight:
self.frame = CGRectMake(0, 0, height, width);
break;
default:
self.frame = CGRectMake(0, 0, width, height);
break;
}
}
- (void)updateWithOrientation:(UIInterfaceOrientation)orientation
{
BOOL isIos7 = [[UIDevice currentDevice].systemVersion floatValue] < 8.0;
BOOL isKeyboardWindow = [self.window isKindOfClass:NSClassFromString(@"UITextEffectsWindow")];
if (isIos7 == YES && isKeyboardWindow == NO) {
[self updateTransformWithOrientation:orientation];
} else {
[self updateFrameWithOrientation:orientation];
}
}
- (void)changeOrientationHandler:(NSNotification *)notification
{
[UIView animateWithDuration:0.25 animations:^{
UIInterfaceOrientation orientation = (UIInterfaceOrientation)[notification.userInfo[UIApplicationStatusBarOrientationUserInfoKey] integerValue];
[self updateWithOrientation:orientation];
}];
}
@end