When developing an iPhone app in Xcode, if you have any requirement that only portrait orientation allowed then you can do the following.
Step 1: Open the implementation file for editing.
Step 2. Navigate to shouldAutorotateToInterfaceOrientation method. This methods is auto generated by Xcode while creating the project.
Step 3: replace the return statement with return (interfaceOrientation == UIInterfaceOrientationPortrait);. The update method should be displayed as shown below.
return (interfaceOrientation == UIInterfaceOrientationPortrait);
This method will return true only when the orientation in Portrait mode.
Step 4: Now navigate to Project Folder on the navigattion bar. In the summary tab under Supported Device Orientations, make sure to un mark the other orientation except portrait.