objective-c – 从模态视图启动摄像头会导致iPad上出现意外调整

ModalViewController *modalController = [[WishlistInfoViewController alloc] initWithNibName:@"WishlistInfoViewController" bundle:nil];

UINavigationController *navController = [[UINavigationController alloc] initWithRootViewController:modalController];
navController.modalPresentationStyle = UIModalPresentationPageSheet; 

self presentViewController:navController animated:YES completion:nil];

navController.view.superview.bounds = CGRectMake(0,700,700);
navController.view.superview.center = CGPointMake(self.view.center.x,self.view.center.y + 35);

在那个模态视图中,我像这样启动相机：

UIImagePickerController *mypicker = [[UIImagePickerController alloc] init];
mypicker.delegate = self; 
mypicker.allowsEditing = NO; 
mypicker.sourceType = UIImagePickerControllerSourceTypeCamera; 
mypicker.showsCameraControls = YES;
mypicker.wantsFullScreenLayout = YES;
[self.navigationController presentModalViewController:mypicker animated:YES];

我这样关掉相机：

[self dismissModalViewControllerAnimated:TRUE];

问题是当我关闭相机时,调整模态视图以填充整个屏幕.我该怎么做才能防止模态视图调整大小？