设备旋转通知没有按照预期的iOS Swift工作

    func shouldirotate(){

    var whichwaywhere: String {

        if UIDevice.currentDevice().orientation == UIDeviceOrientation.LandscapeLeft {
            return "left"
        }
        if UIDevice.currentDevice().orientation == UIDeviceOrientation.LandscapeRight {
            return "right"
        }
        if UIDevice.currentDevice().orientation == UIDeviceOrientation.PortraitUpsideDown {
            return "down"
        }
        return "I don't Care"
    }
    println(whichwaywhere)
}
    func shouldirotate(){

    var whichwaywher