iOS 横竖屏强制转换

强制转成横屏:
// 如果要上传AppStore请慎用，不知道是否能够通过，未尝试
if ([[UIDevice currentDevice] respondsToSelector:@selector(setOrientation:)]) {
SEL selector = NSSelectorFromString(@"setOrientation:");
NSInvocation *invocation = [NSInvocation invocationWithMethodSignature:[UIDevice instanceMethodSignatureForSelector:selector]];
[invocation setSelector:selector];
[invocation setTarget:[UIDevice currentDevice]];
int val = UIInterfaceOrientationLandscapeRight;
[invocation setArgument:&val atIndex:2];
[invocation invoke];
}

通过判断状态栏来设置视图的transform属性。

• (void)deviceOrientationDidChange: (NSNotification *)notification
  {
  UIInterfaceOrientation interfaceOrientation = [[UIApplication sharedApplication] statusBarOrientation];
  CGFloat startRotation = [[self valueForKeyPath:@"layer.transform.rotation.z"] floatValue];
  CGAffineTransform rotation;
  switch (interfaceOrientation) {
  case UIInterfaceOrientationLandscapeLeft:
  rotation = CGAffineTransformMakeRotation(-startRotation + M_PI * 270.0 / 180.0);
  break;
  case UIInterfaceOrientationLandscapeRight:
  rotation = CGAffineTransformMakeRotation(-startRotation + M_PI * 90.0 / 180.0);
  break;
  case UIInterfaceOrientationPortraitUpsideDown:
  rotation = CGAffineTransformMakeRotation(-startRotation + M_PI * 180.0 / 180.0);
  break;
  default:
  rotation = CGAffineTransformMakeRotation(-startRotation + 0.0);
  break;
  }
  view.transform = rotation;
  }