自分の view が表示される前に別のタブで回転されている可能性があるので、回転に対応する処理をプログラムで行う場合は viewWillAppear の中でも処理を行わなくてはならない。

ruby>>
@implementation SomeViewController

• (BOOL)
  shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation {
  return YES;
  }

• (void)
  AdjustHV {
  switch ( self.interfaceOrientation ) {
  case UIInterfaceOrientationPortrait:
  case UIInterfaceOrientationPortraitUpsideDown:
  oV1.frame = CGRectMake(
  0
  , 0
  , self.view.frame.size.width
  , self.view.frame.size.height / 2
  );
  oV2.frame = CGRectMake(
  0
  , self.view.frame.size.height / 2
  , self.view.frame.size.width
  , self.view.frame.size.height / 2
  );
  break;
  case UIInterfaceOrientationLandscapeLeft:
  case UIInterfaceOrientationLandscapeRight:
  oV1.frame = CGRectMake(
  0
  , 0
  , self.view.frame.size.width / 2
  , self.view.frame.size.height
  );
  oV2.frame = CGRectMake(
  self.view.frame.size.width / 2
  , 0
  , self.view.frame.size.width / 2
  , self.view.frame.size.height
  );
  break;
  }
  }

• (void)
  viewWillAppear:(BOOL)p {
  [ super viewWillAppear:p ];
  [ self AdjustHV ];
  }

• (void)
  willAnimateRotationToInterfaceOrientation:(UIInterfaceOrientation)p
  duration:(NSTimeInterval)pDuration {
  [ super willAnimateRotationToInterfaceOrientation:p duration:pDuration ];
  [ self AdjustHV ];
  }
  @end
  <<--