Catransform3d 将Calayer作为子视图合并并翻转到CATTransferMlayer

根据前面的stackoverflow建议，我正在尝试使用添加到CATTransferMlayer的CALayers创建一张扑克牌。其想法是创建前后Calayer，并将它们组合在CATTransfermLayer中，然后可以旋转、翻转等，并自动显示正确的一面。下面是尝试创建一张正面为绿色背面为红色的卡片的示例代码

红色背面围绕Y轴翻转，使其背对绿色正面。绿色正面的calayer比红色背面的Z位置“更高”

不过，当我进行转换时，我只是看到卡处于非翻转状态。你知道我哪里做错了吗

#define DEGREES_TO_RADIANS(angle) (angle * M_PI / 180.0)

- (void)viewDidLoad
{
    [super viewDidLoad];

    CATransformLayer *cardContainer = [CATransformLayer layer];

    cardContainer.bounds = CGRectMake(0,0, 150,200);


    CALayer *cardFront  = [CALayer layer];
    cardFront.frame     = cardContainer.bounds;

    cardFront.backgroundColor = [UIColor greenColor].CGColor;
    cardFront.borderColor = [UIColor blackColor].CGColor;
    cardFront.borderWidth = 2.0;
    cardFront.cornerRadius = 30.0;
    cardFront.zPosition = 2; // Put front of card on top relative to back of card
    cardFront.doubleSided = NO;
    [cardContainer addSublayer:cardFront];

    CALayer *cardBack  = [CALayer layer];
    cardBack.frame     = cardContainer.bounds;
    cardBack.backgroundColor = [UIColor redColor].CGColor;
    cardBack.zPosition = 1;
    cardBack.doubleSided = NO;

    // Flip cardBack image so it is facing outward and visible when flipped
    cardBack.transform = CATransform3DMakeRotation(DEGREES_TO_RADIANS(180),0.0,1.0,0.0);
    [cardContainer addSublayer:cardBack];

    UIView* cardView = [[UIView alloc] initWithFrame:cardContainer.bounds];
    cardView.center = CGPointMake(self.view.center.x, self.view.center.y);
    [cardView.layer addSublayer:cardContainer];
    [self.view addSubview:cardView];

    // Show the card flipped over (desired the red side to be showing, but instead shows green)
    cardView.layer.transform = CATransform3DMakeRotation(DEGREES_TO_RADIANS(180),0.0,1.0,0.0);

}

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发现问题后，必须将转换应用于sublayerTransform属性，如中所示：

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cardView.layer.sublayerTransform=…

发现问题，必须将转换应用于sublayerTransform属性，如中所示：

cardView.layer.sublayerTransform=