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[viewB convertRect:viewC.frame toView:viewA];
viewA是目标，viewC是被操作的对象，那么剩下的viewB自然而然就是源了。作用就是计算viewB上的viewC相对于viewA的frame。
[viewC convertRect:viewB.frame fromView:viewA];
该例子viewA是源，viewB是被操作的对象，那么viewC就是目标。作用就是计算viewA上的viewB相对于viewC的frame。
先从文档来
UIViewControllerContextTransitioning
UIViewControllerAnimatedTransitioning
自定义简单转场动画上面两个protocol结合下面这两个方法就可以搞.
- (NSTimeInterval)transitionDuration:(nullable id <UIViewControllerContextTransitioning>)transitionContext;
// This method can only be a nop if the transition is interactive and not a percentDriven interactive transition.
- (void)animateTransition:(id <UIViewControllerContextTransitioning>)transitionContext;
还需要注意navigation的代理
UINavigationControllerDelegate
下面这个代理方法返回的是 就是上面UIViewControllerAnimatedTransitioning.
- (nullable id <UIViewControllerAnimatedTransitioning>)navigationController:(UINavigationController *)navigationController
animationControllerForOperation:(UINavigationControllerOperation)operation
fromViewController:(UIViewController *)fromVC
toViewController:(UIViewController *)toVC NS_AVAILABLE_IOS(7_0);
为了完成动画还需要了解一个函数
- (nullable UIView *)snapshotViewAfterScreenUpdates:(BOOL)afterUpdates NS_AVAILABLE_IOS(7_0);
这个函数是获取view或者什么什么控件上的，截屏。afterUpdates是否全显示之后再截屏。
下面要开始了。
从第一步开始。
遵守代理
UINavigationControllerDelegate
self.navigationController.delegate = self;
#pragma mark -- UINavigationControllerDelegate
- (id<UIViewControllerAnimatedTransitioning>)navigationController:(UINavigationController *)navigationController animationControllerForOperation:(UINavigationControllerOperation)operation fromViewController:(UIViewController *)fromVC toViewController:(UIViewController *)toVC {
if (operation == UINavigationControllerOperationPush) {
return [customNavgationPushTransition new];//如果是push的话用我们定义的那个对象push对象
} else if (operation == UINavigationControllerOperationPop && fromVC != self) {
return [customNavgationPopTransition new];
} else {
return nil;
}
}
如果没有这一步，自定义的专场动画也就不会生效。因为没有返回UIViewControllerAnimatedTransitioning。
第二步，自定义push动画
//动画时长
- (NSTimeInterval)transitionDuration:(nullable id <UIViewControllerContextTransitioning>)transitionContext {
return 0.5;
}
//
- (void)animateTransition:(id <UIViewControllerContextTransitioning>)transitionContext {
//1.获取动画的源控制器和目标控制器
ViewController *fromVC = [transitionContext viewControllerForKey:UITransitionContextFromViewControllerKey];
DetailViewController *toVC = [transitionContext viewControllerForKey:UITransitionContextToViewControllerKey];
UIView *container = [transitionContext containerView];
//2.创建一个 imageView 的截图，并把 imageView 隐藏，造成使用户以为移动的就是 imageView 的假象
UIView *snapshotView = [fromVC.ImageView snapshotViewAfterScreenUpdates:NO];
//计算fromVC.view上的fromVC.ImageView.frame相对于container的坐标
snapshotView.frame = [container convertRect:fromVC.ImageView.frame fromView:fromVC.view];
// fromVC.selectedCell.imageView.hidden = YES;
//3.设置目标控制器的位置，并把透明度设为0，在后面的动画中慢慢显示出来变为1
toVC.view.frame = [transitionContext finalFrameForViewController:toVC];
toVC.view.alpha = 0;
toVC.bgImageView.hidden = YES;
//4.都添加到 container 中。注意顺序不能错了
[container addSubview:toVC.view];
[container addSubview:snapshotView];
[UIView animateWithDuration:[self transitionDuration:transitionContext] delay:0 options:UIViewAnimationOptionCurveEaseInOut animations:^{
snapshotView.frame = [container convertRect:toVC.bgImageView.frame fromView:toVC.view];
fromVC.view.alpha = 0;
toVC.view.alpha = 1;
} completion:^(BOOL finished) {
fromVC.ImageView.hidden = NO;
toVC.bgImageView.hidden = NO;
[snapshotView removeFromSuperview];
//一定要记得动画完成后执行此方法，让系统管理 navigation 如果设置为no。可以自己试试
[transitionContext completeTransition:YES];
}];
}
完成这一步那么push的时候就会有动画了。
第三步设置pop动画，跟push大同小异。
//动画时长
- (NSTimeInterval)transitionDuration:(nullable id <UIViewControllerContextTransitioning>)transitionContext {
return 0.5;
}
//
- (void)animateTransition:(id <UIViewControllerContextTransitioning>)transitionContext {
//1.获取动画的源控制器和目标控制器
DetailViewController *fromVC = [transitionContext viewControllerForKey:UITransitionContextFromViewControllerKey];
ViewController *toVC = [transitionContext viewControllerForKey:UITransitionContextToViewControllerKey];
UIView *container = [transitionContext containerView];
//2.创建一个 Cell 中 imageView 的截图，并把 imageView 隐藏，造成使用户以为移动的就是 imageView 的假象
UIView *snapshotView = [fromVC.bgImageView snapshotViewAfterScreenUpdates:NO];
snapshotView.frame = [container convertRect:fromVC.bgImageView.frame fromView:fromVC.view];
fromVC.bgImageView.hidden = YES;
//3.设置目标控制器的位置，并把透明度设为0，在后面的动画中慢慢显示出来变为1
toVC.view.frame = [transitionContext finalFrameForViewController:toVC];
toVC.view.alpha = 0;
// toVC..hidden = YES;
//4.都添加到 container 中。注意顺序不能错了
[container addSubview:toVC.view];
[container addSubview:snapshotView];
[UIView animateWithDuration:[self transitionDuration:transitionContext] delay:0 options:UIViewAnimationOptionCurveEaseInOut animations:^{
snapshotView.frame = [container convertRect:toVC.ImageView.frame fromView:toVC.view];
fromVC.view.alpha = 0;
toVC.view.alpha = 1;
} completion:^(BOOL finished) {
fromVC.bgImageView.hidden = NO;
// toVC.selectedCell.hidden = NO;
[snapshotView removeFromSuperview];
//一定要记得动画完成后执行此方法，让系统管理 navigation
[transitionContext completeTransition:YES];
}];
}
demo地址(https://github.com/Butteryflyyer/XH_CustomTransitionl)
