上一篇文章介绍了三种简单的转场动画,全部代码在这里
这里说另外两种
第一种动画(AdaptivePresentation)
其实乍一看这个从底部弹出来的感觉不就是Modal么，对，没错，用Modal可以很简单的实现。但是既然说自定义，那就看看是怎么自定义出来的。附图Modal的效果，在目标控制器插入一个NavigationController就能实现了。
首先目标控制器要遵循UIAdaptivePresentationControllerDelegate协议
- (void)setTransitioningDelegate:(id<UIViewControllerTransitioningDelegate>)transitioningDelegate{
[super setTransitioningDelegate:transitioningDelegate];
self.presentationController.delegate = self;
}
#pragma mark- UIAdaptivePresentationControllerDelegate
- (UIModalPresentationStyle)adaptivePresentationStyleForPresentationController:(UIPresentationController *)controller{
return UIModalPresentationFullScreen;
}
- (UIViewController *)presentationController:(UIPresentationController *)controller viewControllerForAdaptivePresentationStyle:(UIModalPresentationStyle)style{
return [[UINavigationController alloc]initWithRootViewController:controller.presentedViewController];
}
说个插曲，由于用的是storyboard拖线的，这个时候要选择Custom的
但是如果直接选择Custom的话会报以下错误，让你重写- perform方法
#import <UIKit/UIKit.h>
@interface AdaptiveStoryboardSegue : UIStoryboardSegue
@end
#import "AdaptiveStoryboardSegue.h"
#import "AdaptivePresentationController.h"
@implementation AdaptiveStoryboardSegue
//如果没有实现transitioningDelegate 此时不会报错，但是呈现出来的效果跟Modal出来的一样
- (void)perform {
UIViewController *sourceController = self.sourceViewController;//官方的demo这里是destinationViewController,但是结果没有影响
UIViewController *desitinationController = self.destinationViewController;
AdaptivePresentationController *presentationViewController = [[AdaptivePresentationController alloc]initWithPresentedViewController:desitinationController presentingViewController:sourceController];
desitinationController.transitioningDelegate = presentationViewController;
[sourceController presentViewController:desitinationController animated:YES completion:nil];
}
@end
其他的跟上一篇自定义转场动画的套路是一样的，主要的代码还是在UIViewControllerAnimatedTransitioning里面，在源码里面我写了很多注释，就不一一在这里说明了。
说个小技巧，可以看出我在secondViewController写的是
[self performSegueWithIdentifier:@"backtoFirstViewController" sender:sender];
但是可以在storyboard里面并没有看到有Segue的连线，只有跳转到secondViewController的连线，那么是怎么让它跳转回去的呢？
点击secondViewController，我们可以看到这样
有一根Segue并且有一个identifier和action，那么这个事件是怎么回事的呢？原来这个事件是写在源控制器里的
//这个方法并不是随便添加的，而是为了在secondViewController的Exit连接事件的时候有这个action，就可以返回到当前的控制器
- (IBAction)backtoFirstViewController:(UIStoryboardSegue *)sender{
}
然后点击secondViewController的Exit就可以看到这样方法，把这个方法连线到secondViewController上就可以了。
第二种动画(Checkboard)
第二个动画思路是：在containerView上面有一层黑色的view，按照某一个固定的尺寸切割等分，然后双层嵌套循环创建很多个view添加到当前的黑色的view 。然后计算出哪些view将要3D旋转。
可以看出是对系统本身的UINavigationController的动画做了自定义
查了一些资料，navigation controller有一个方法，代理来检索有没有animator objec对象来作用在传入的试图控制器上，如果这个方法实现了，将返回一个遵守了UIViewControllerAnimatedTransitioning协议的对象 如果没有的话就默认是push或者pop动画,这个方法就是
- (nullable id <UIViewControllerAnimatedTransitioning>)navigationController:(UINavigationController *)navigationController
animationControllerForOperation:(UINavigationControllerOperation)operation
fromViewController:(UIViewController *)fromVC
toViewController:(UIViewController *)toVC{
}
返回的是一个遵守UIViewControllerAnimatedTransitioning协议的对象，主要的代码还是在这里面，但是有一段代码看的我整个人都不好了，求 大神指教
//计算当前正在飞行的片数 从这里开始整个人懵逼了 看不懂
__block NSUInteger sliceAnimationsPending = 0;
for (NSInteger y = 0; y <verticalSlices; y ++) {
for (NSInteger x = 0; x < horizontalSlices; x ++) {
UIView *toCheckboardView = transitionContainer.subviews[y * horizontalSlices * 2 + (x * 2)];
UIView *fromCheckboardView = transitionContainer.subviews[y * horizontalSlices * 2 + (x * 2 + 1)];
CGVector sliceOriginVector;
if (isPush) {
sliceOriginVector = CGVectorMake(CGRectGetMinX(fromCheckboardView.frame) - CGRectGetMinX(transitionContainer.bounds),
CGRectGetMinY(fromCheckboardView.frame) - CGRectGetMinY(transitionContainer.bounds));
}else{
sliceOriginVector = CGVectorMake(CGRectGetMaxX(fromCheckboardView.frame) - CGRectGetMaxX(transitionContainer.bounds),
CGRectGetMaxY(fromCheckboardView.frame) - CGRectGetMaxY(transitionContainer.bounds));
}
CGFloat dot = sliceOriginVector.dx * transitionVector.dx + sliceOriginVector.dy * transitionVector.dy;
CGVector projection = CGVectorMake(transitionUnitVector.dx * dot/transitionVectorLength,
transitionUnitVector.dy * dot/transitionVectorLength);
CGFloat projectionLength = sqrtf( projection.dx * projection.dx + projection.dy * projection.dy );
NSTimeInterval startTime = projectionLength/(transitionVectorLength + transitionSpacing) * transitionDuration;
NSTimeInterval duration = ( (projectionLength + transitionSpacing)/(transitionVectorLength + transitionSpacing) * transitionDuration ) - startTime;
sliceAnimationsPending++;
[UIView animateWithDuration:duration delay:startTime options:0 animations:^{
toCheckboardView.layer.transform = CATransform3DIdentity;
fromCheckboardView.layer.transform = CATransform3DMakeRotation(M_PI, 0, 1, 0);
} completion:^(BOOL finished) {
if (--sliceAnimationsPending == 0) {
BOOL wasCancelled = [transitionContext transitionWasCancelled];
[transitionContainer removeFromSuperview];
[transitionContext completeTransition:!wasCancelled];
}
}];
}
}
