思路：
控制器A 控制器B 中各有一个圆形按钮，点击A中白色按钮会Push到B控制器
自定义动画部分 创建动画类继承NSObject遵循UIViewControllerAnimatedTransitioning协议，实现以下方法
- (void)animateTransition:(id<UIViewControllerContextTransitioning>)transitionContext;
- (NSTimeInterval)transitionDuration:(id<UIViewControllerContextTransitioning>)transitionContext;
计算小圆和大圆的圆心和半径，用CABasicAnimation 绘制路径动添加画即可
CABasicAnimation *anim = [CABasicAnimation animation];
anim.fromValue = (id)smallPath.CGPath;
anim.toValue = bigPath;
A B控制器都要遵循UINavigationControllerDelegate 代理和实现以下方法 -(id)navigationController:(UINavigationController*)navigationController animationControllerForOperation:(UINavigationControllerOperation)operation fromViewController:(UIViewController*)fromVC toViewController:(UIViewController*)toVC{
//事例
A B控制器都要遵循UINavigationControllerDelegate 代理和实现以下方法
- (id)navigationController:(UINavigationController*)navigationController animationControllerForOperation:(UINavigationControllerOperation)operation fromViewController:(UIViewController*)fromVC toViewController:(UIViewController*)toVC{
if (operation == UINavigationControllerOperationPush) {
TMTransition *trans = [TMTransition new];
trans.isPush=YES;
returntrans;
}else{
returnnil;
}
}
//在此方法中实现具体的转场动画
- (void)animateTransition:(id)transitionContext{
//1.持有上下文
_context= transitionContext;
//2.获取一个view的容器
UIView*containerView = [transitionContextcontainerView];
//3.获取tovc的view，然后添加到容器里面
UIViewController *toVC = [transitionContext viewControllerForKey:UITransitionContextToViewControllerKey];
//4.添加动画
UIButton*btn;
ViewController *VC1;
TMBlueController *VC2;
if(_isPush) {
VC1 = [transitionContextviewControllerForKey:UITransitionContextFromViewControllerKey];
VC2 = [transitionContextviewControllerForKey:UITransitionContextToViewControllerKey];
btn = VC1.mFirstBtn;
}else{
VC2 = [transitionContextviewControllerForKey:UITransitionContextFromViewControllerKey];
VC1 = [transitionContextviewControllerForKey:UITransitionContextToViewControllerKey];
btn = VC2.mBlueBtn;
}
[containerViewaddSubview:VC1.view];
[containerViewaddSubview:VC2.view];
//5.画一个小圆(大小圆的中心点是一样)
UIBezierPath *smallPath = [UIBezierPath bezierPathWithOvalInRect:btn.frame];
//6.中心点
CGPointcenterP;
centerP = btn.center;
//7.求大圆的半径
CGFloatradius;
//8.判断按钮在哪个象限
CGFloat y = CGRectGetHeight(toVC.view.frame)-btn.center.y;
CGFloat x = CGRectGetWidth(toVC.view.frame) - btn.center.x;
if (btn.frame.origin.x > CGRectGetWidth(toVC.view.frame)/2) {
if (btn.frame.origin.y < CGRectGetHeight(toVC.view.frame)/2) {
//1
radius =sqrtf(btn.center.x*btn.center.x+ y*y);
}else{
//4
radius =sqrtf(btn.center.x*btn.center.x+ btn.center.y*btn.center.y);
}
}else{
if (CGRectGetMaxY(btn.frame) < CGRectGetHeight(toVC.view.frame)/2) {
//2
radius =sqrtf(x*x + y*y);
}else{
//3
radius =sqrtf(btn.center.y*btn.center.y+ x*x);
}
}
//9.用贝塞尔画大圆
UIBezierPath *bigPath = [UIBezierPath bezierPathWithArcCenter:centerP radius:radius startAngle:0 endAngle:M_PI*2 clockwise:YES];
//10.把path添加到layer
CAShapeLayer *shapeLayer = [CAShapeLayer layer];
if(_isPush) {
shapeLayer.path= bigPath.CGPath;
}else{
shapeLayer.path= smallPath.CGPath;
}
//11.蒙板
UIViewController *VC;
if(_isPush) {
VC = [transitionContextviewControllerForKey:UITransitionContextToViewControllerKey];
}else{
VC = [transitionContextviewControllerForKey:UITransitionContextFromViewControllerKey];
}
VC.view.layer.mask= shapeLayer;
//12.动画
CABasicAnimation *anim = [CABasicAnimation animation];
anim.keyPath=@"path";
if(_isPush) {
anim.fromValue= (id)smallPath.CGPath;
}else{
anim.fromValue= (id)bigPath.CGPath;
}
// anim.toValue = bigPath;
anim.delegate=self;
[shapeLayeraddAnimation:animforKey:nil];
}
#pragma mark - CAAnimationDelegate
- (void)animationDidStop:(CAAnimation*)anim finished:(BOOL)flag{
[_context completeTransition:YES];
UIViewController *VC;
if(_isPush) {
VC = [_context viewControllerForKey:UITransitionContextToViewControllerKey];
}else{
VC = [_context viewControllerForKey:UITransitionContextFromViewControllerKey];
}
VC.view.layer.mask = nil;
}
完整demo:
