转场动画

方法1: 利用控制器的 transitionFromViewController:toViewController: ... 方法转场,from, to两个控制器必须是同一个控制器的子控制器

    BigPhotoViewController *bigVc = [[BigPhotoViewController alloc] init];
    
    [self addChildViewController:bigVc];
    
    bigVc.image = self.array[indexPath.item];
//    [self presentViewController:bigVc animated:YES completion:nil];
    
    bigVc.view.alpha = 0.0;
    // 1. 利用控制器的 transitionFromViewController:toViewController: ... 方法转场,from, to两个控制器必须是同一个控制器的子控制器
    
    [self transitionFromViewController:self.vc1  toViewController:bigVc duration:0.5 options:UIViewAnimationOptionCurveLinear animations:^{
        
        bigVc.view.alpha = 1.0;
        
    } completion:nil];

方法2: 利用CoreAnimation的CATransition

    BigPhotoViewController *bigVc = [[BigPhotoViewController alloc] init];

    bigVc.image = self.array[indexPath.item];

    // 2. 利用CATransition
    CATransition *transition = [CATransition animation];
    transition.type = @"cube";
    
    [self.view.layer addAnimation:transition forKey:nil];
    
    [self presentViewController:bigVc animated:YES completion:nil];

方法3: 利用转场代理transitioningDelegate

- (void)collectionView:(UICollectionView *)collectionView didSelectItemAtIndexPath:(NSIndexPath *)indexPath
{

    BigPhotoViewController *bigVc = [[BigPhotoViewController alloc] init];

    bigVc.image = self.array[indexPath.item];
    bigVc.modalPresentationStyle = UIModalPresentationCustom;
    
    // 3. 利用转场代理
    
    bigVc.transitioningDelegate = self.animator;
    self.animator.delegate = self;
    self.animator.indexPath = indexPath;
    
    [self presentViewController:bigVc animated:YES completion:nil];
    
}

需要遵守协议的对象animator做代理

@interface BigPhotoAnimator : NSObject  

// 自定义遵守协议的对象, 实现下面方法(present时 / dismiss时各一个)
#pragma mark - 
// 出现时的动画对象
- (id)animationControllerForPresentedController:(UIViewController *)presented presentingController:(UIViewController *)presenting sourceController:(UIViewController *)source
{
    self.isPresentAnimate = YES;
    return self;
}

/*
 * 消失时的动画对象
 */
- (id)animationControllerForDismissedController:(UIViewController *)dismissed
{
    self.isPresentAnimate = NO;
    return self;
    
}

这两个方法的返回对象必须遵守协议, 可以返回自定义对象本身,让该对象遵守协议,实现以下方法

#pragma mark - 

// 动画时间
- (NSTimeInterval)transitionDuration:(id)transitionContext
{
    
    return 0.5;
}

// 具体动画实现
- (void)animateTransition:(id)transitionContext
{
    // 通过上下文获得from控制器
    UIViewController *fromVc = [transitionContext viewControllerForKey:UITransitionContextFromViewControllerKey];
    
    // 通过上下文获得to控制器
    UIViewController *toVc = [transitionContext viewControllerForKey:UITransitionContextToViewControllerKey];
    
    // 通过上下文获得from的view
    UIView *fromView = [transitionContext viewForKey:UITransitionContextFromViewKey];
    // 通过上下文获得to的view
    UIView *toView = [transitionContext viewForKey:UITransitionContextToViewKey];

    // 获取动画时间
    NSTimeInterval duration = [self transitionDuration:transitionContext];
    
    if (self.isPresentAnimate) {  // 弹出动画
        
        toView.alpha = 0.0;
        UIImage *image = nil;
        CGRect rect = CGRectZero;
        
        
        // 自定义协议,通过代理实现协议的方法获得要做动画的imageView的图片和大小
        if (_delegate) {
            image = [_delegate animator:self ImageForIndexPath:self.indexPath];
            rect = [_delegate animator:self RectForIndexPath:self.indexPath];
        }
        
        UIImageView *imageView = [[UIImageView alloc] initWithImage:image];
        imageView.frame = rect;
        
        // 把要动画的view添加到containerView  记得!!
        [[transitionContext containerView] addSubview:toView];
        [[transitionContext containerView] addSubview:imageView];
        
        
        toView.alpha = 0.0;
        
        // 动画实现
        [UIView animateWithDuration:duration animations:^{
            
            
            imageView.frame = [UIScreen mainScreen].bounds;
            
        } completion:^(BOOL finished) {
            
            [imageView removeFromSuperview];
            toView.alpha = 1.0;
            
            // 通过上下文通知动画结束
            [transitionContext completeTransition:YES];
        }];
        
    }
    else {  // 消失动画
        
        
        toView.alpha = 0.0;
        
        UIImage *image = nil;
        CGRect rect = CGRectZero;
        
        // 自定义协议,通过代理实现协议的方法获得要做动画的imageView的图片和大小
        if (_delegate) {
            
            image = [_delegate animator:self ImageForIndexPath:self.indexPath];
            rect = [_delegate animator:self RectForIndexPath:self.indexPath];
        }
        
        UIImageView *imageView = [[UIImageView alloc] initWithImage:image];
        imageView.frame = [UIScreen mainScreen].bounds;
        
        
        // 添加到containerView
        [[transitionContext containerView] addSubview:imageView];
        [[transitionContext containerView] addSubview:fromView];
        
        fromView.alpha = 0.0;
        
        // 动画实现
        [UIView animateWithDuration:duration animations:^{
            
            imageView.frame = rect;
            
        } completion:^(BOOL finished) {
            
            [imageView removeFromSuperview];
            
            
            // 通过上下文通知动画结束
            [transitionContext completeTransition:YES];
        }];
        
    }