iOS - Flip animation only for specific view

问题:

i'm developing a game which contained some view (as memory card game) and i want that when the user tap on a card this flip and shows another view. I use this code :

- (void)flipCard:(id)sender {

    UIButton *btn=(UIButton *)sender;
    UIView *view=[btn superview];
    UIView *flipView=[[UIView alloc] initWithFrame:[view frame]];
    [flipView setBackgroundColor:[UIColor blueColor]];
    [[flipView layer] setCornerRadius:10];

    NSLog(@"Flip card : view frame = %f, %f",view.frame.origin.x, view.frame.origin.y);

    [UIView transitionFromView:view toView:flipView duration:1.0 options:UIViewAnimationOptionTransitionFlipFromLeft completion:^(BOOL finished) {
    }];

}

Every view has a transparent button which cover the entire view, so when user tap on a view is as tap the button. The button call the method above passing the sender. When the animation starts all view is flipped, not only the view i get from sender. How can i do?

回答1:

The following code might help with your problem. I think it is cleaner than using a transparent button.

- (void)viewDidLoad {
    [super viewDidLoad];

    flipped = NO;
    UITapGestureRecognizer *tapGesture = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(handleTap:)];

    [flipContainerView addGestureRecognizer:tapGesture];
    [tapGesture release];
}

- (void)handleTap:(UITapGestureRecognizer *)sender {
    if (sender.state == UIGestureRecognizerStateEnded) {
        [UIView transitionWithView:flipContainerView
                          duration:1
                           options:UIViewAnimationOptionTransitionFlipFromLeft
                        animations:^{

            if (!flipped) {
                [frontCard setHidden:YES];
                [flipContainerView addSubview:backCard.view]; //or unhide it.
                flipped = YES;
            } else {
                [frontCard setHidden:NO];
                [backCard removeFromSuperview]; //or hide it.
            }

        } completion:nil];
    }
}

回答2:

I had the same problem. After searching different posts on the internet I was able to come up with an elegant and easy solution. I have the cards as custom UIButtons. In the custom UIButton class I added the method which changes the background image with a flip animation:

-(void) flipCard{
    [UIView transitionWithView:self
                      duration:0.3f
                       options:UIViewAnimationOptionTransitionFlipFromRight|UIViewAnimationOptionCurveEaseInOut
                    animations:^{
                        if (self.isFlipped) {
                            [self setBackgroundImage:[UIImage imageNamed:@"card_back_2.png"] forState:UIControlStateNormal];
                        }else{
                            [self setBackgroundImage:[UIImage imageNamed:self.cardName] forState:UIControlStateNormal];
                        }
                    } completion:NULL];
    self.isFlipped = !self.isFlipped;
}

Hope this helps someone else as the first answer has been already accepted

UPDATE

If you are on the view containing this sub-view the code is:

-(void)flipCard:(APCard*)card{
    [UIView transitionWithView:card
                      duration:kFlipTime
                       options:UIViewAnimationOptionTransitionFlipFromRight|UIViewAnimationOptionCurveEaseInOut
                    animations:^{
                        if (card.isFlipped) {
                            [card setBackgroundImage:[UIImage imageNamed:@"card_back_2.png"] forState:UIControlStateNormal];
                        }else{
                            [card setBackgroundImage:[UIImage imageNamed:card.cardName] forState:UIControlStateNormal];
                        }
                    completion:^(BOOL finished) {
                         if (finished) {
                             //DO Stuff
                         }
                     }
    ];
    card.isFlipped = !card.isFlipped;
}

回答3:

My use case in Swift 4:

@IBAction func flipCard() {
                let transitionOptions: UIView.AnimationOptions = [.transitionFlipFromRight, .showHideTransitionViews]

        UIView.transition(with: letterView, duration: 1.0, options: transitionOptions, animations: {
            if self.showingBack == true {
                self.letterImage.image = UIImage.init(named: self.letterImageName + ".png")
                self.letterNameLabel.text = self.regularWord
                self.showingBack = false
            } else {
                self.letterImage.image = UIImage.init(named: self.letterImageName + "C.png")
                self.letterNameLabel.text = self.cursiveWord
                self.showingBack = true
            }
        })
    }