Objective-C 使用核心动画CAAnimation实现动画先来看看效果吧Demo地址

CABasicAnimation          //经典动画
CAKeyframeAnimation       //关键帧动画
CATransition              //转场动画
CAAnimationGroup          //组动画

//startView变小
- (void)startViewChangeSmaller {

    //设置一组动画
    //变小
    CABasicAnimation *animation1 = [[CABasicAnimation alloc] init];
    animation1.keyPath = @"bounds";
    animation1.toValue = [NSValue valueWithCGRect:CGRectMake(0, 0, kStartRadius*2, kStartRadius*2)];
    //变圆
    CABasicAnimation *animation2 = [[CABasicAnimation alloc] init];
    animation2.keyPath = @"cornerRadius";
    animation2.toValue = [NSNumber numberWithFloat:kStartRadius];
    //加入组动画
    CAAnimationGroup *group = [[CAAnimationGroup alloc] init];
    group.animations = @[animation1,animation2];
    group.removedOnCompletion = NO;
    group.fillMode = kCAFillModeForwards;
    group.duration = kAnimationDuration;
    group.delegate = self;
    [self.startView.layer addAnimation:group forKey:nil];
    self.layer.masksToBounds = YES;
    
    [self performSelector:@selector(startViewBackAnimation) withObject:nil afterDelay:kAnimationDuration];
}

//通过曲线路径将startView移到中间
- (void)startViewToCenter {
    
    //设置贝塞尔曲线路径动画
    UIBezierPath *path = [UIBezierPath bezierPath];
    [path moveToPoint:self.startView.center];
    [path addCurveToPoint:CGPointMake(self.frame.size.width/2, self.frame.size.height/2 ) controlPoint1:CGPointMake(self.frame.size.width - kStartRadius, 0 ) controlPoint2:CGPointMake(self.frame.size.width * 1.3, self.frame.size.height/2)];
    CAKeyframeAnimation *anmiation0 = [CAKeyframeAnimation animationWithKeyPath:@"position"];
    anmiation0.path = path.CGPath;
    anmiation0.duration = kAnimationDuration;
    anmiation0.removedOnCompletion = NO;
    anmiation0.fillMode = kCAFillModeForwards;
    [self.startView.layer addAnimation:anmiation0 forKey:nil];
    [self performSelector:@selector(startViewChangeAnimation) withObject:nil afterDelay:1];
}

//响应超出view的事件
- (BOOL)pointInside:(CGPoint)point withEvent:(UIEvent *)event {
    return YES;
}