IPad iOS development basics-iPad device Direction recognition

 

 

because Apple requires iPad applications to provide at least portrait and landscape support, therefore, in the Program , it is essential to detect the current direction of the device. Generally, it can be used in the program running:
1 [[uidevice currentdevice] orientation];
To obtain the current device direction, but if the program starts, the result is:
1 uideviceorientationunknown
In fact, you can obtain the direction of the Controller to which the control belongs, so that the direction of the control is consistent with that of the controller, you do not need to care about the current device direction.
example:
1 If (self. interfaceorientation = uideviceorientationportrait)
you can determine whether the program is in the protrait direction at startup.