目标C：

NSNumber *orientationValue = [NSNumber numberWithInt:UIInterfaceOrientationPortrait];
[[UIDevice currentDevice] setValue:orientationValue forKey:@"orientation"];

斯威夫特：

let orientationValue = UIInterfaceOrientation.Portrait.rawValue
UIDevice.currentDevice().setValue(orientationValue, forKey: "orientation")

override func supportedInterfaceOrientations() -> UIInterfaceOrientationMask {
    return UIInterfaceOrientationMask.Portrait
}

请尝试以下操作：

override func shouldAutorotate() -> Bool {
    return onlyPortarit()
 }

 override func supportedInterfaceOrientations() -> UIInterfaceOrientationMask {
    return UIInterfaceOrientationMask.Portrait
 }

 func onlyPortarit() -> Bool{
    if(UIDevice.currentDevice().orientation == UIDeviceOrientation.Portrait ||
        UIDevice.currentDevice().orientation == UIDeviceOrientation.PortraitUpsideDown ||
        UIDevice.currentDevice().orientation == UIDeviceOrientation.Unknown){
            return true
    }else{
        return false
    }
 }

除了Manuel的回应外，在viewDidLoad()中添加以下内容

UIDevice.current.setValue(UIInterfaceOrientation.portrait.rawValue, forKey: "orientation")

这将初始化纵向ViewController，无论设备方向如何。