iOS 转场动画_NAV_图片缩放效果
林劲
#import "ZJNavTransition.h"
#define SCREENHEIGHT [UIScreen mainScreen].bounds.size.height
@interface ZJNavTransition()
/** 判断转场同**/
@property (nonatomic, assign) ZJNavTransitionType type;
/** 缩放图片**/
@property (nonatomic, strong) UIImage *image;
@end
/** 小图的原始位置**/
static NSIndexPath *initIndexPath;
/** 小图的返回位置**/
static NSIndexPath *returnIndexPath;
/** 小图的原始大小**/
static CGRect initFrame;
/** 小图的collectionview视图**/
static UICollectionView *smallCollectionView;
/** 一行有几个**/
static NSInteger rowItemCount = 4;
/** 导航栏高度如果没有导航栏这就填0**/
static NSInteger NAVHeight = 64;
@implementation ZJNavTransition
+ (instancetype)transitionWithType:(ZJNavTransitionType)type WithImage:(UIImage *)image
{
return [[self alloc] initTransitionWithType:type WithImage:image];
}
- (instancetype)initTransitionWithType:(ZJNavTransitionType)type WithImage:(UIImage *)image
{
if (self = [super init])
{
_type = type;
_image = image;
}
return self;
}
//动画时间
- (NSTimeInterval)transitionDuration:(nullable id <UIViewControllerContextTransitioning>)transitionContext
{
return 0.5;
}
//执行哪一种动画
- (void)animateTransition:(id <UIViewControllerContextTransitioning>)transitionContext
{
switch (_type) {
case ZJNavTransitionPush:
[self doPushAnimateTransition:transitionContext];
break;
case ZJNavTransitionPop:
[self doPopAnimateTransition:transitionContext];
break;
}
}
- (void)doPushAnimateTransition:(id <UIViewControllerContextTransitioning>)transitionContext
{
//拿到两个控制器
UIViewController *fromVC = [transitionContext viewControllerForKey:UITransitionContextFromViewControllerKey];
UIViewController *toVC = [transitionContext viewControllerForKey:UITransitionContextToViewControllerKey];
//找到CollectionView
for (UICollectionView *view in fromVC.view.subviews)
{
if ([view isKindOfClass:[UICollectionView class]])
{
smallCollectionView = view;
}
}
initIndexPath = [smallCollectionView indexPathsForSelectedItems][0];
UICollectionViewCell *cell = [smallCollectionView cellForItemAtIndexPath:initIndexPath];
//获取过渡用的视图
UIView *containerView = [transitionContext containerView];
UIImageView *imageView = [[UIImageView alloc] init];
[containerView addSubview:toVC.view];
[containerView addSubview:imageView];
//设置动画前各个控件的状态
fromVC.view.hidden = YES;
toVC.view.alpha = 0;
for (UIView *view in toVC.view.subviews)
{
view.hidden = YES;
}
//算坐标，
// CGFloat x = cell.frame.origin.x;
// CGFloat y = cell.frame.origin.y - _detailsCollectionView.contentOffset.y;
// CGFloat orgWight = cell.frame.size.width;
// CGFloat orgHeight = cell.frame.size.height;
// initFrame =CGRectMake(x, y, orgWight, orgHeight);
//设置图片开始在cell的位置，转换cell的位置信息给动画图片
imageView.frame = [cell convertRect:cell.bounds toView:containerView];
initFrame = imageView.frame;
//获取要缩放的图片
imageView.image = _image;
//设置图片进行缩放后的高和宽
CGFloat height = imageView.image.size.height * (fromVC.view.frame.size.width / imageView.image.size.width);
CGFloat wight = fromVC.view.frame.size.width;
//让图片变大放在屏幕中央
[UIView animateWithDuration:[self transitionDuration:transitionContext] animations:^{
imageView.frame = CGRectMake(0, ((fromVC.view.frame.size.height + NAVHeight) / 2) - (height / 2), wight, height);
toVC.view.alpha = 1;
} completion:^(BOOL finished) {
for (UIView *view in toVC.view.subviews)
{
view.hidden = NO;
}
imageView.hidden = YES;
//如果动画过渡取消了就标记不完成，否则才完成，这里可以直接写YES，如果有手势过渡才需要判断，必须标记，否则系统不会中动画完成的部署，会出现无法交互之类的bug
[transitionContext completeTransition:YES];
}];
}
- (void)doPopAnimateTransition:(id <UIViewControllerContextTransitioning>)transitionContext
{
//这里是缩小回去的动画,fromVC是大图浏览界面的控制器，toVC是小图浏览界面的控制器。
UIViewController *fromVC = [transitionContext viewControllerForKey:UITransitionContextFromViewControllerKey];
UIViewController *toVC = [transitionContext viewControllerForKey:UITransitionContextToViewControllerKey];
UICollectionView *BigImageCollectionView;
//找到CollectionView
for (UIView *view in fromVC.view.subviews)
{
if ([view isKindOfClass:[UICollectionView class]])
{
BigImageCollectionView = (UICollectionView *)view;
}
}
if (!BigImageCollectionView)
{
for (UIView *view in fromVC.view.subviews)
{
for (UICollectionView *collectionView in view.subviews)
{
if ([collectionView isKindOfClass:[UICollectionView class]])
{
BigImageCollectionView = collectionView;
}
}
}
}
//得到大图页面的cell，主要是为了用那张图片，因为动画的图片用的是大图
UICollectionViewCell *bigImageCell = BigImageCollectionView.visibleCells[0];
//在这里拿到大图界面返回时候的indexPath
returnIndexPath = [BigImageCollectionView indexPathForCell:bigImageCell];
//这里是之前点击的小图的位置
// NSIndexPath *initIndexPath = toVC.indexPath;
//这里做一个判断，如果是同一行，那么就不用改变contentSize
if ((returnIndexPath.item / rowItemCount) != (initIndexPath.item / rowItemCount))
{
//算出原始的cell距离屏幕边缘有几行（用到屏幕边缘的距离对cell的高度取整），如果要返回的cell在下面就用屏幕减去原始cell的最大Y值，否则就用原始的Y值
NSInteger rowCount = returnIndexPath.item > initIndexPath.item ? (SCREENHEIGHT - 64 - CGRectGetMaxY(initFrame)) / initFrame.size.height : initFrame.origin.y / initFrame.size.height;
//得到要返回的cell距离开始的cell距离几个item
NSInteger abs = returnIndexPath.item - initIndexPath.item;
//当前的位置距离原始位置几行
NSInteger distanceCount = labs(abs) / rowItemCount;
//距离的格子数目小于rowItemCount格（一行就rowItemCount格），那么久让行数加一
labs(abs) < rowItemCount ? distanceCount++ : distanceCount;
//当前距离原始的行数大于原始距离屏幕的行数，就需要滚动
if (distanceCount > rowCount)
{
//得到contentSize需要增加或减少的长度
NSInteger scrollCount = abs > 0 ? distanceCount : -distanceCount;
//如果
if(labs(abs) % rowItemCount != 0)
{
if (scrollCount > 0)
{
scrollCount += 1;
}
else
{
scrollCount -= 1;
}
}
smallCollectionView.contentOffset =(CGPoint){0, smallCollectionView.contentOffset.y + (initFrame.size.height + 2) * scrollCount};
}
}
//得到要返回的cell，根据indexPath
UICollectionViewCell *currendCell = [smallCollectionView cellForItemAtIndexPath:returnIndexPath];
//这里就是过渡动画的那个视图了
UIView *containerView = [transitionContext containerView];
//这里的lastView就是push时候初始化的那个tempView
UIImageView *tempView = containerView.subviews.lastObject;
tempView.image = _image;
//设置初始状态
currendCell.hidden = YES;
fromVC.view.hidden = YES;
tempView.hidden = NO;
toVC.view.hidden = NO;
[containerView insertSubview:toVC.view atIndex:0];
//一个蒙版遮住原来位置的图
UIView *view;
if (!currendCell)
{
view = [[UIView alloc] initWithFrame:[self returnFrameWithIndexPath:returnIndexPath AndInitFrame:initFrame]];
view.backgroundColor = toVC.view.backgroundColor;
[toVC.view addSubview:view];
}
[UIView animateWithDuration:[self transitionDuration:transitionContext] animations:^{
if (currendCell)
{
tempView.frame = [currendCell convertRect:currendCell.bounds toView:containerView];
}
else
{
tempView.frame = [self returnFrameWithIndexPath:returnIndexPath AndInitFrame:initFrame];
}
fromVC.view.alpha = 0;
} completion:^(BOOL finished) {
//如果加入了手势必须判断
[transitionContext completeTransition:![transitionContext transitionWasCancelled]];
if ([transitionContext transitionWasCancelled]) {//手势取消了，原来隐藏的imageView要显示出来
//失败了隐藏tempView，显示fromVC.imageView
tempView.hidden = YES;
fromVC.view.hidden = NO;
}else{//手势成功，cell的imageView也要显示出来
//成功了移除tempView，下一次pop的时候又要创建，然后显示cell的imageView
currendCell.hidden = NO;
[tempView removeFromSuperview];
if (!currendCell)
{
[view removeFromSuperview];
}
}
}];
}
#pragma mark - 计算返回的坐标
- (CGRect)returnFrameWithIndexPath:(NSIndexPath *)indexPath AndInitFrame:(CGRect)initFrame
{
CGFloat returnWidth = initFrame.size.width;
CGFloat returnHeight = initFrame.size.height;
CGFloat returnX = (indexPath.item % rowItemCount) * (initFrame.size.width + 2);
CGFloat returnY = initFrame.origin.y;
return (CGRect){returnX, returnY, returnWidth, returnHeight};
}
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