Ios 如何将这一目标c traitCollection转化为swift？

我正试图从这个链接用目标C翻译这段代码

以下是我试图翻译的代码：

@interface RDTraitCollectionOverrideViewController : UIViewController {
BOOL _willTransitionToPortrait;
UITraitCollection *_traitCollection_CompactRegular;
UITraitCollection *_traitCollection_AnyAny;
}

@end

@implementation RDTraitCollectionOverrideViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    [self setUpReferenceSizeClasses];
}

- (void)setUpReferenceSizeClasses {
    UITraitCollection *traitCollection_hCompact = [UITraitCollection traitCollectionWithHorizontalSizeClass:UIUserInterfaceSizeClassCompact];
UITraitCollection *traitCollection_vRegular = [UITraitCollection traitCollectionWithVerticalSizeClass:UIUserInterfaceSizeClassRegular];
_traitCollection_CompactRegular = [UITraitCollection traitCollectionWithTraitsFromCollections:@[traitCollection_hCompact, traitCollection_vRegular]];

UITraitCollection *traitCollection_hAny = [UITraitCollection traitCollectionWithHorizontalSizeClass:UIUserInterfaceSizeClassUnspecified];
UITraitCollection *traitCollection_vAny = [UITraitCollection traitCollectionWithVerticalSizeClass:UIUserInterfaceSizeClassUnspecified];
_traitCollection_AnyAny = [UITraitCollection traitCollectionWithTraitsFromCollections:@[traitCollection_hAny, traitCollection_vAny]];
}

-(void)viewWillAppear:(BOOL)animated {
_willTransitionToPortrait = self.view.frame.size.height > self.view.frame.size.width;
}

- (void)viewWillTransitionToSize:(CGSize)size withTransitionCoordinator:(id<UIViewControllerTransitionCoordinator>)coordinator {
_willTransitionToPortrait = size.height > size.width;
}

-(UITraitCollection *)overrideTraitCollectionForChildViewController:(UIViewController *)childViewController {
UITraitCollection *traitCollectionForOverride =           (_willTransitionToPortrait) ? _traitCollection_CompactRegular :    _traitCollection_AnyAny;
return traitCollectionForOverride;
}
@end

}

我想我几乎拥有了所有功能，但最后一个功能我不知道它转换成什么。非常感谢您的帮助。

我认为您在上一个函数中缺少“override”，请尝试用以下代码替换：

override func overrideTraitCollectionForChildViewController(childViewController: UIViewController) -> UITraitCollection! {
    //
}

以下是完整的代码：

导入UIKit
类ViewController:UIViewController{
变量：Bool=false
var compactRegular=UITraitCollection（）
var anyAny=UITraitCollection（）
重写func viewDidLoad（）{
super.viewDidLoad（）
//加载视图后，通常从nib执行任何其他设置。
setUpReferenceSizeClasses（）
}
func setUpReferenceSizeClasses（）{
var traitCollection\u hCompact=UITraitCollection（horizontalSizeClass:UIUserInterfaceSizeClass.Compact）
var traitCollection\u vRegular=UITraitCollection（垂直大小类：UIUserInterfaceSizeClass.Regular）
compactRegular=UITraitCollection（traitsFromCollections:[traitCollection\u hCompact，traitCollection\u vRegular]）
var traitCollection\u hAny=UITraitCollection（horizontalSizeClass:UIUserInterfaceSizeClass.Unspecified）
var traitCollection\u vAny=UITraitCollection（垂直大小类：UIUserInterfaceSizeClass.Unspecified）
anyAny=UITraitCollection（traitsFromCollections:[traitCollection\u hAny，traitCollection\u vAny]）
}
覆盖功能视图将出现（动画：Bool）{
WillTransitionTorait=self.view.frame.size.height>self.view.frame.size.width
}
重写func ViewWillTransitionSize（大小：CGSize，带TransitionCoordinator协调器：UIViewControllerTransitionCoordinator）{
WillTransitionTorait=size.height>size.width
}
override func overrideTraitCollectionForChildViewController（childViewController:UIViewController）->UITraitCollection{
//
var traitCollectionForOverride=（WilltTransitionToractive）？compactRegular:anyAny
返回traitCollectionForOverride；
}
重写函数didReceiveMemoryWarning（）{
超级。我收到了记忆警告（）
//处置所有可以重新创建的资源。
}
}

override func overrideTraitCollectionForChildViewController(childViewController: UIViewController) -> UITraitCollection! {
    //
}