UIInterfaceOrientation方向枚举:
UIInterfaceOrientationPortrait //home健在下
UIInterfaceOrientationPortraitUpsideDown //home健在上
UIInterfaceOrientationLandscapeLeft //home健在左
UIInterfaceOrientationLandscapeRight //home健在右
旋转屏幕时触发的函数: //旋转方向发生改变时 -(void)willAnimateRotationToInterfaceOrientation:(UIInterfaceOrientation)toInterfaceOrientation duration:(NSTimeInterval)duration { } //视图旋转动画前一半发生之前自动调用 -(void)willAnimateFirstHalfOfRotationToInterfaceOrientation:(UIInterfaceOrientation)toInterfaceOrientation duration:(NSTimeInterval)duration { } //视图旋转动画后一半发生之前自动调用 -(void)willAnimateSecondHalfOfRotationFromInterfaceOrientation:(UIInterfaceOrientation)fromInterfaceOrientation duration:(NSTimeInterval)duration { } //视图旋转之前自动调用 -(void)willRotateToInterfaceOrientation:(UIInterfaceOrientation)toInterfaceOrientation duration:(NSTimeInterval)duration { } //视图旋转完成之后自动调用 -(void)didRotateFromInterfaceOrientation:(UIInterfaceOrientation)fromInterfaceOrientation { } //视图旋转动画前一半发生之后自动调用 -(void)didAnimateFirstHalfOfRotationToInterfaceOrientation:(UIInterfaceOrientation)toInterfaceOrientation { }