iOS切换视图控制器取决于设备方向(iOS switching view controllers depending on the device orientation)

 我正在开发一个增强现实应用程序，一切正常，直到现在我需要两种不同的可视化（AR和Map），具体取决于设备方向。 特别是当设备处于横向模式时，应用程序应使用landscapeViewController，而当设备的方向为“正面朝上”时，应使用另一个控制器（名为faceUpViewController）。 我尝试使用两个简单的视图控制器，它工作正常。 当landscapeViewController使用AR控制器时会发生此问题。 视图完全是白色的，我不明白为什么。 这两个控制器都由Root View Controller“包含”。 我正在通过编码来做所有事情，所以没有nib文件。 这是代码： 
 
 RootViewController.m 
 
- (void)viewDidLoad
{
    [super viewDidLoad];
    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(deviceOrientationDidChange:) name:UIDeviceOrientationDidChangeNotification object:nil];
    [[UIDevice currentDevice] beginGeneratingDeviceOrientationNotifications];
}

- (void)deviceOrientationDidChange:(NSNotification *)notification{

    UIDeviceOrientation orientation = [[UIDevice currentDevice] orientation];

    if (orientation == UIDeviceOrientationLandscapeLeft) {
        if (self.landscapeViewController.view.superview == nil) {
            if (self.landscapeViewController == nil) {
                LandscapeViewController *lvc = [[LandscapeViewController alloc] init];
                self.landscapeViewController = lvc;
                [lvc release];
            }
            [self.faceUpViewController.view removeFromSuperview];
            [self.view addSubview:self.landscapeViewController.view];
        }
    }

    if (orientation == UIDeviceOrientationFaceUp) {
        if (self.faceUpViewController.view.superview == nil) {
            if (self.faceUpViewController == nil) {
                FaceUpViewController *fvc = [[FaceUpViewController alloc] init];
                self.faceUpViewController = fvc;
                [fvc release];
            }
            [self.landscapeViewController.view removeFromSuperview];
            [self.view addSubview:self.faceUpViewController.view];
        }
    }

}

@end
 
 LandscapeViewController.m 
 
// Implement loadView to create a view hierarchy programmatically, without using a nib.
- (void)loadView
{
    UIView *landscapeView = [[UIView alloc] initWithFrame:CGRectMake(0, 0, 1024, 768)];
    landscapeView.backgroundColor = [UIColor yellowColor];
    self.view = landscapeView;
    [landscapeView release];

    ARController *arC = [[ARController alloc] initWithViewController:self];
    arC.landscapeViewController = self;
    self.arController = arC;
    [arC release];
}

//When the view appear present the camera feed
- (void)viewDidAppear:(BOOL)animated { 
    [super viewDidAppear:animated]; 
    [_arController presentModalARControllerAnimated:NO];
}
 
 FaceUpViewController.m 
 
- (void)loadView
{
    UIView *faceUpView = [[UIView alloc] initWithFrame:CGRectMake(0, 0, 1024, 768)];
    faceUpView.backgroundColor = [UIColor blueColor];
    self.view = faceUpView;
    [faceUpView release];
}
 
 ARController.m非常简单的版本 
 
- (id) initWithViewController:(UIViewController *)theView{

    if ([UIImagePickerController isSourceTypeAvailable:UIImagePickerControllerSourceTypeCamera]) {

        self.rootController = theView; 

        //Retrieve screen bounds
        CGRect screenBounds = [[UIScreen mainScreen] bounds]; 

        UIView *overlaidView = [[UIView alloc] initWithFrame: screenBounds];
        self.overlayView =  overlaidView;
        [overlaidView release];
        self.rootController.view = overlayView;

        // Initialise the UIImagePickerController 
        UIImagePickerController *picker= [[UIImagePickerController alloc] init];
        self.pickerController = picker;
        [picker release];

        self.pickerController.sourceType = UIImagePickerControllerSourceTypeCamera; 
        self.pickerController.cameraViewTransform = CGAffineTransformScale(
                                                                           self.pickerController.cameraViewTransform, 1.0f, 1.12412f);

        self.pickerController.showsCameraControls = NO; 
        self.pickerController.navigationBarHidden = YES; 
        self.pickerController.cameraOverlayView = _overlayView;
    }

    return self;
}

- (void)presentModalARControllerAnimated:(BOOL)animated{
    [self.rootController presentModalViewController:[self pickerController] animated:animated]; 
    self.overlayView.frame = self.pickerController.view.bounds;
}

@end
 
 我再说一遍，我通过编码从而没有nib文件。 我非常感谢任何建议！ 谢谢 

I'm developing an Augmented Reality application, everything worked properly till now that I need two different kind of visualization (AR and Map) depending on the device orientation. In particular the application should use the landscapeViewController when the device is in landscape mode while it should use another controller (named faceUpViewController ) when the device's orientation is "face up". I tried doing it with two simple view controllers and it works fine. The problem happens when the landscapeViewController uses the AR controller. The view is completely white and I don't understand why. Both the two controllers are "contained" by a Root View Controller. I'm doing everything by coding so without nib files. Here is the code:
 
RootViewController.m
 
- (void)viewDidLoad
{
    [super viewDidLoad];
    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(deviceOrientationDidChange:) name:UIDeviceOrientationDidChangeNotification object:nil];
    [[UIDevice currentDevice] beginGeneratingDeviceOrientationNotifications];
}

- (void)deviceOrientationDidChange:(NSNotification *)notification{

    UIDeviceOrientation orientation = [[UIDevice currentDevice] orientation];

    if (orientation == UIDeviceOrientationLandscapeLeft) {
        if (self.landscapeViewController.view.superview == nil) {
            if (self.landscapeViewController == nil) {
                LandscapeViewController *lvc = [[LandscapeViewController alloc] init];
                self.landscapeViewController = lvc;
                [lvc release];
            }
            [self.faceUpViewController.view removeFromSuperview];
            [self.view addSubview:self.landscapeViewController.view];
        }
    }

    if (orientation == UIDeviceOrientationFaceUp) {
        if (self.faceUpViewController.view.superview == nil) {
            if (self.faceUpViewController == nil) {
                FaceUpViewController *fvc = [[FaceUpViewController alloc] init];
                self.faceUpViewController = fvc;
                [fvc release];
            }
            [self.landscapeViewController.view removeFromSuperview];
            [self.view addSubview:self.faceUpViewController.view];
        }
    }

}

@end
 
LandscapeViewController.m
 
// Implement loadView to create a view hierarchy programmatically, without using a nib.
- (void)loadView
{
    UIView *landscapeView = [[UIView alloc] initWithFrame:CGRectMake(0, 0, 1024, 768)];
    landscapeView.backgroundColor = [UIColor yellowColor];
    self.view = landscapeView;
    [landscapeView release];

    ARController *arC = [[ARController alloc] initWithViewController:self];
    arC.landscapeViewController = self;
    self.arController = arC;
    [arC release];
}

//When the view appear present the camera feed
- (void)viewDidAppear:(BOOL)animated { 
    [super viewDidAppear:animated]; 
    [_arController presentModalARControllerAnimated:NO];
}
 
FaceUpViewController.m
 
- (void)loadView
{
    UIView *faceUpView = [[UIView alloc] initWithFrame:CGRectMake(0, 0, 1024, 768)];
    faceUpView.backgroundColor = [UIColor blueColor];
    self.view = faceUpView;
    [faceUpView release];
}
 
ARController.m Very simple version
 
- (id) initWithViewController:(UIViewController *)theView{

    if ([UIImagePickerController isSourceTypeAvailable:UIImagePickerControllerSourceTypeCamera]) {

        self.rootController = theView; 

        //Retrieve screen bounds
        CGRect screenBounds = [[UIScreen mainScreen] bounds]; 

        UIView *overlaidView = [[UIView alloc] initWithFrame: screenBounds];
        self.overlayView =  overlaidView;
        [overlaidView release];
        self.rootController.view = overlayView;

        // Initialise the UIImagePickerController 
        UIImagePickerController *picker= [[UIImagePickerController alloc] init];
        self.pickerController = picker;
        [picker release];

        self.pickerController.sourceType = UIImagePickerControllerSourceTypeCamera; 
        self.pickerController.cameraViewTransform = CGAffineTransformScale(
                                                                           self.pickerController.cameraViewTransform, 1.0f, 1.12412f);

        self.pickerController.showsCameraControls = NO; 
        self.pickerController.navigationBarHidden = YES; 
        self.pickerController.cameraOverlayView = _overlayView;
    }

    return self;
}

- (void)presentModalARControllerAnimated:(BOOL)animated{
    [self.rootController presentModalViewController:[self pickerController] animated:animated]; 
    self.overlayView.frame = self.pickerController.view.bounds;
}

@end
 
I say again that I'm doing everything by coding thereby without nib files. I really appreciate any advice! Thanks

原文：https://stackoverflow.com/questions/8406465