iOS design orientation issue for Universal application - ios

Question

HI I am developing an iOS Universal application for both orientation Portrait and Landscape
I am using following code for adjusting my UI according to orientation change
- (void)viewDidLoad
{
[[NSNotificationCenter defaultCenter] addObserver:self
selector:#selector(deviceOrientationDidChange:)
name:UIDeviceOrientationDidChangeNotification
object:nil];
}
- (void)deviceOrientationDidChange:(NSNotification *)notification
{
[self changeTheOrientation];
}
- (void)changeTheOrientation
{
UIInterfaceOrientation orientation = [UIApplication sharedApplication].statusBarOrientation;
if (UI_USER_INTERFACE_IDIOM() == UIUserInterfaceIdiomPad)
{
if ( UIDeviceOrientationIsPortrait(orientation))
{
//For Portrait set frame size
lblBookInfo.frame = CGRectMake (0, 20, 718, 50);
btnClose.frame = CGRectMake (718, 20, 50, 50);
}
else if (UIDeviceOrientationIsLandscape(orientation))
{
//For Landscape set frame size
lblBookInfo.frame = CGRectMake (0, 20, 974, 50);
btnClose.frame = CGRectMake (974, 20, 50, 50);
}
}
else
{
if (UIDeviceOrientationIsPortrait(orientation))
{
//For Portrait set frame size
lblBookInfo.frame = CGRectMake (0, 20, 290, 30);
btnClose.frame = CGRectMake (290, 20, 30, 30);
}
else if (UIDeviceOrientationIsLandscape(orientation))
{
//For Landscape set frame size
if ( [[UIScreen mainScreen] bounds].size.height==568 ) {
} else {
}
}
}
}
The basic code structure which I am using for handling different UI frame with change in orientation is above.
But the problem which i am facing is that the UIDeviceOrientationDidChangeNotification is not fired every time , I think it gets missed for some times , I have checked this by setting proper breakpoints , this problem makes look my Ui really bad as sometimes UI do not change accordingly to the frame.
This approach works properly for some initial UI changes but get failed after some (10-20)orientation changes.
Is it the correct approach which I am using or is there any better approach to handle different orientations in iOS
I am developing app for (iOS 6 and iOS 7).

Answer 1

Use the following code to detect orientation in the callback for the UIDeviceOrientationDidChangeNotification -
UIDeviceOrientation deviceOrientation = [UIDevice currentDevice].orientation;
Then to detect if it is landscape or portairt you can -
if (UIDeviceOrientationIsLandscape(deviceOrientation) {
//do landscape related view changes
} else if (UIDeviceOrientationIsPortrait(deviceOrientation) {
//do portrait related view changes
}
I have seen this line being added before registering for orientation change notifications. Usually in awakeFromNib method -
[[UIDevice currentDevice] beginGeneratingDeviceOrientationNotifications];
Then register for notifications -
[[NSNotificationCenter defaultCenter] addObserver:self
selector:#selector(deviceOrientationDidChange:)
name:UIDeviceOrientationDidChangeNotification
object:nil];