效果图:
1.封装好的工具类(可以根据需求改变圆心的位置再封装)
WeCircleAnimation.h文件
#import<Foundation/Foundation.h>
#import<UIKit/UIKit.h>
@interface WeCircleAnimation :NSObject<UIViewControllerTransitioningDelegate>
@end
WeCircleAnimation.m文件
@interface WeCircleAnimation ()<UIViewControllerAnimatedTransitioning,CAAnimationDelegate>
//动画是呈现还是解除
@property (nonatomic, assign) BOOL isPresented;
//保存动画上下文(必须要弱引用,如果强引用则会导致循环引用,内存泄露)
@property (nonatomic, weak) id<UIViewControllerContextTransitioning> transitionContext;
@end
@implementation WeCircleAnimation
//告诉控制器谁来提供展现转场动画
- (nullable id)animationControllerForPresentedController:(UIViewController *)presented presentingController:(UIViewController *)presenting sourceController:(UIViewController *)source{
self.isPresented = YES; return self;
}
//告诉控制器谁来提供解除转场动画
- (nullable id)animationControllerForDismissedController:(UIViewController *)dismissed{
self.isPresented = NO;
return self;
}
/** 返回动画时长 @param transitionContext 转场上下文 @return 转场动画 */
- (NSTimeInterval)transitionDuration:(nullable id)transitionContext{
return 0.3;
}
** 转场动画最核心的方法-有程序员提供自己的动画实现 @param transitionContext 转场上下文提供转场动画的所有细节 容器视图-转场动画的表演的舞台 转场上下文会对展现的控制器强引用 */
- (void)animateTransition:(id)transitionContext{
//1.获取容器视图
UIView *containerView = transitionContext.containerView;
//2.获取目标视图,如果是展现去toView,如果是解除,去fromView;
UIView *fromView = [transitionContext viewForKey:UITransitionContextFromViewKey];
UIView *toView = [transitionContext viewForKey:UITransitionContextToViewKey];
UIView *view = self.isPresented?toView:fromView;
NSLog(@"%@---%@",fromView,toView);
//3.添加目标视图到容器视图
[containerView addSubview:view];
//4.动画
[self layerAnimationWithView:view];
//5.一定要完成转场,如果不完成,系统会一直等待转场完成,就无法接收用户的任何交互
//应该在动画完成之后在通知系统转场结束
self.transitionContext = transitionContext;
}
-(void)layerAnimationWithView:(UIView *)view{
//1.创建形状图层ShapeLayer
CAShapeLayer *shapeLayer = [[CAShapeLayer alloc] init];
//圆的屏幕边距
CGFloat mergin = 20;
//圆的半径
CGFloat radiu = 25;
CGRect startRect = CGRectMake(view.bounds.size.width - mergin - radiu*2, mergin, radiu*2, radiu*2);
//2.创建圆形贝塞尔路径 参数是圆的外界矩形
UIBezierPath *startBezierPath = [UIBezierPath bezierPathWithOvalInRect:startRect];
CGFloat sWidth = view.bounds.size.width;
CGFloat sHeight = view.bounds.size.height;
//结束圆的半径(屏幕的半径)
CGFloat endRadius = sqrt(sWidth * sWidth + sHeight * sHeight);
//使用缩进矩形创建圆的外接矩形
CGRect endRect = CGRectInset(startRect, -endRadius, -endRadius);
//3.外接圆的的贝塞尔路径
UIBezierPath *endPath = [UIBezierPath bezierPathWithOvalInRect:endRect];
//设置形状图层的填充颜色 fillColor:填充圆 strokeColor:边框圆
// shapeLayer.fillColor = [UIColor redColor].CGColor;
//4.绘制号的贝塞尔路径为形状图层的路径
shapeLayer.path = startBezierPath.CGPath;
//设置shapeLayer为控制器视图的遮罩图层
//5.设置mask遮罩图层:1.会裁切图层,让图层只能看见shapelayer的形状的区域 2.一旦将layer设置为遮罩图层之后,填充颜色会失效
view.layer.mask = shapeLayer;
//将shape添加到视图中,addSublayer实在当前的图层上添加一个layer的形状区域
// [self.view.layer addSublayer:shapeLayer];
//5.动画 -如果要做layer视图的动画，不能使用UIView的动画，应该使用核心动画
// [UIView animateWithDuration:3 animations:^{
// //设置图层的路径
// layer.path = endPath.CGPath;
//
// }];
//6.实例化对象
CABasicAnimation *animation = [CABasicAnimation animationWithKeyPath:@"path"];
//7.设置动画的属性:1.时间 2.填充模式
//设置动画属性
//时长
animation.duration = [self transitionDuration:self.transitionContext];
//判断是展现还是解除
if (self.isPresented) {
//formValue
animation.fromValue = (__bridge id _Nullable)(startBezierPath.CGPath);
animation.toValue = (__bridge id _Nullable)(endPath.CGPath);
}else{
animation.fromValue = (__bridge id _Nullable)(endPath.CGPath);
animation.toValue = (__bridge id _Nullable)(startBezierPath.CGPath);
}
//设置向前填充模式
animation.fillMode = kCAFillModeForwards;
//完成之后不删除
animation.removedOnCompletion = NO;
//设置动画代理 必须要写在添加动画到图层的前面,否则代理不会调用(一旦将动画添加到图层,动画已经开启,在设置代理已经来不及了)
animation.delegate = self;
//8.将动画添加到图层 -shapeLayer,让哪个图层执行动画就应该将动画添加到哪个图层
[shapeLayer addAnimation:animation forKey:nil];
}
/**
监听动画完成
@param anim 动画
@param flag 完成
*/
- (void)animationDidStop:(CAAnimation *)anim finished:(BOOL)flag{
[self.transitionContext completeTransition:YES];
}
@end
运用:
ViewController.m
#import "ViewController.h"
#import "WeCircleAnimation.h"
@interface ViewController ()
@property (nonatomic, strong) WeCircleAnimation *circleAnnimation;
@end
@implementation ViewController
-(void)awakeFromNib{
[super awakeFromNib];
//1.设置展示样式为自定义
self.modalPresentationStyle = UIModalPresentationCustom;
//2.设置转场代理
self.circleAnnimation = [[WeCircleAnimation alloc]init]; self.transitioningDelegate = self.circleAnnimation;
}
- (void)viewDidLoad { [super viewDidLoad];}-(void)touchesBegan:(NSSet*)touches withEvent:(UIEvent *)event{
[self dismissViewControllerAnimated:YES completion:nil];
}
@end
storyBoard中的控件效果图
