segue - 切换到模态视图时 iAD 消失

Question

我有一个用于横向模式的独特 viewController，问题是当我转到横向视图控制器（模态 segue）时，iAD 消失了，而且它似乎也停止接收委托方法。只有当我点击标签栏以转到另一个视图然后再次返回时，它才会再次显示

- (void)orientationChanged:(NSNotification *)notification

{
    NSLog(@"orientation changed");
    UIDeviceOrientation deviceOrientation = [UIDevice currentDevice].orientation;

    if (UIDeviceOrientationIsLandscape(deviceOrientation) && !isShowingLandscapeView && isThisView)
    {
        //[self.view bringSubviewToFront:self.backgroundImageView];
        [self performSegueWithIdentifier:@"DisplayLandscapeView" sender:self];
        isShowingLandscapeView = YES;
    }

    else if (deviceOrientation ==  UIDeviceOrientationPortrait && isShowingLandscapeView)
    {
        [self dismissViewControllerAnimated:YES completion:nil];
        isShowingLandscapeView = NO;
        self.bannerView.hidden = NO;
        //[self.view sendSubviewToBack:self.backgroundImageView];
    }
}