objective-c - 将枚举值分配给 Obj-C 中的属性

Question

我在 Swift 中有以下代码。我如何将其转换为 Objective-C？ (是的，从 Swift 到 Objective-C)；)

class PopAnimator: NSObject, UIViewControllerAnimatedTransitioning {

    enum PopTransitionMode: Int {
        case Present, Dismiss
    }

    var transitionMode: PopTransitionMode = .Present

}

我在 Obj-C 中尝试了以下方法，我不确定如何将 PopTr​​ansitionMode 的值类型分配给我的属性。

// .h
typedef NS_ENUM(NSInteger, PopTransitionMode) {
    Present,
    Dismiss
};
@interface PopAnimator : NSObject <UIViewControllerAnimatedTransitioning>
@property (nonatomic, assign) PopTransitionMode transitionMode;
@end


// .m
@implementation PopAnimator

-(id)init {

   if (self = [super init]) {

       _transitionMode = ???

   }


   return self;
}

@end

Answer 1

您可以只使用枚举值。有了更好的命名，像这样枚举:

typedef NS_ENUM(NSInteger, PopTransitionMode) {
    PopTransitionModePresent,
    PopTransitionModeDismiss
};

像这样初始化:

// if the initializer takes a param
- (id)initWithTransitionMode:(PopTransitionMode)transitionMode {
    self = [self init];
    if (self) {
        _transitionMode = transitionMode;
    }
   return self;
}

// OR, if the initializer hard-codes a param
- (id)init {
    self = [super init];
    if (self) {
        _transitionMode = PopTransitionModeDismiss;
    }
   return self;
}