App hanging after three times of orientation

I have a UIviewController with a pdf in it. I use the orientation in another screen to display the pdf. The orientation works well three times and then the app hangs with the below warning.

[Switching to process 11779 thread 0x0]

[Switching to process 13059 thread 0x0]

[Switching to process 11779 thread 0x0]

What does it says? Please find the code below.

- (void)viewDidLoad
{
  self.view.backgroundColor = [UIColor clearColor];
  pdfURL = [NSURL fileURLWithPath:[[NSBundle mainBundle]                    pathForResource:@"Sample" ofType:@"pdf"]];
[webView loadRequest:[NSURLRequest requestWithURL:pdfURL]];       
thisDevice = [UIDevice currentDevice];  
[thisDevice beginGeneratingDeviceOrientationNotifications];    
[[UIDevice currentDevice] beginGeneratingDeviceOrientationNotifications];            
[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(detectOrientation) name:UIDeviceOrientationDidChangeNotification object:nil];
[self setTitle:@"1 Of 1"];
[super viewDidLoad];
}

-(void) detectOrientation
{    
if (([[UIDevice currentDevice] orientation] == UIDeviceOrientationLandscapeLeft) || 
    ([[UIDevice currentDevice] orientation] == UIDeviceOrientationLandscapeRight)) {

    //load view 2

    IdcardVC *ids = [[IdcardVC alloc] initWithNibName:@"IdcardVC" bundle:nil];
[self.navigationController presentModalViewController:ids animated:YES];
[ids release];
} 
else if ([[UIDevice currentDevice] orientation] == UIDeviceOrientationPortrait) 开发者_如何转开发{

     [self dismissModalViewControllerAnimated:NO];
}

Any help is appreciated. Thank You

---

Instead of doing this complicated task you should use the default method provided ios to deal with orientation stuff:

Just Add thee following code to your .m file:

// Override to allow orientations other than the default portrait orientation.
- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation {
// Return YES for supported orientations.
return YES;
}