如何以横向模式正确打开我的应用程序答案

【问题标题】：How to correctly open my application in landscape mode如何以横向模式正确打开我的应用程序
【发布时间】：2016-04-11 08:13:39
【问题描述】：

我有一个视图控制器，我在其中添加了一个 UIView 全屏大小，在那个 UIView 中我有 AVCapturesession 可以帮助我捕捉照片，我的视图控制器在纵向模式下打开良好，但在横向模式下突然打开。

代码如下，

- (void)viewDidLoad {
  [super viewDidLoad];
  self.view.backgroundColor = [UIColor whiteColor];
  [[UIDevice currentDevice]beginGeneratingDeviceOrientationNotifications];
  [[NSNotificationCenter defaultCenter]addObserver:self selector:@selector(orientationDidChange:) name:UIDeviceOrientationDidChangeNotification object:nil];
  self.camera.userInteractionEnabled = YES;
  UIPinchGestureRecognizer *pinchGesture = [[UIPinchGestureRecognizer alloc]initWithTarget:self action:@selector(handlePinchGesture:)];
  pinchGesture.delegate=self;
  [self.camera addGestureRecognizer:pinchGesture];
  [self.navigationController setNavigationBarHidden:YES animated:YES];
}

相机是 UIView，它是我的 UIViewController 的属性，

再次，

-(void) viewDidAppear:(BOOL)animated
{
  AVCaptureSession *session = [[AVCaptureSession alloc] init];
  session.sessionPreset = AVCaptureSessionPresetMedium;

  CALayer *viewLayer = self.camera.layer;
  NSLog(@"viewLayer = %@", viewLayer);
  captureVideoPreviewLayer = [[AVCaptureVideoPreviewLayer alloc] initWithSession:session];

  captureVideoPreviewLayer.frame = self.camera.layer.bounds;
  [self.camera.layer addSublayer: captureVideoPreviewLayer];
  device = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];
  NSError *error = nil;
  AVCaptureDeviceInput *input = [AVCaptureDeviceInput deviceInputWithDevice:device error:&error];
  if (!input) {
    // Handle the error appropriately.
    NSLog(@"ERROR: trying to open camera: %@", error);
  }
  [session addInput:input];

  [session startRunning];
  stillImageOutput = [[AVCaptureStillImageOutput alloc] init];
  NSDictionary *outputSettings = [[NSDictionary alloc] initWithObjectsAndKeys: AVVideoCodecJPEG, AVVideoCodecKey, nil];
  [stillImageOutput setOutputSettings:outputSettings];

  [session addOutput:stillImageOutput];

  isUsingFlash = NO;
  isUsingFrontFacingCamera = NO;
  effectiveScale = 1.0;
}

我的视图在横向模式下打开错误，一旦我旋转到纵向它会很好，再次旋转到横向它工作良好，只是它在横向模式下无法正常启动，为什么？

这里我设置的是根视图控制器，

 sb = [UIStoryboard storyboardWithName:@"Main" bundle:nil];
 cameraFirstController = [sb instantiateViewControllerWithIdentifier:@"FirstViewController"];
 cameraFirstController.delegate = self;
 nav = [[CustomNavigationController alloc]initWithRootViewController:cameraFirstController];
 [self.viewController presentViewController:nav animated:YES completion:nil];

【问题讨论】：

你能在设置 rootViewController 的地方添加代码吗？
我已在您编辑的答案中添加了代码。请检查

标签： ios objective-c uiview autolayout landscape-portrait

【解决方案1】：

似乎问题是设置窗口时的调用顺序。在分配rootViewController 之前，您需要调用makeKeyAndVisible。

self.window = [[UIWindow alloc] initWithFrame:[UIScreen mainScreen].bounds];
[self.window makeKeyAndVisible];
self.window.rootViewController = self.YourViewController;

【讨论】：