Question

我创建了一个沿着bezier路径移动的平面动画。当用户滑动某个方向时，有没有办法启动动画？（即如果用户向右平移，则平面沿路径向右移动。如果用户向左平移，则平面沿路径向左移动）。

感谢您的帮助。

Answer 1

曲线设置：

self.trackPath = [UIBezierPath bezierPath];
self.trackPath = [UIBezierPath bezierPathWithArcCenter:P(self.scrollView.center.x,self.scrollView.center.y-20)
                               radius:110
                           startAngle:DEGREES_TO_RADIANS(70)
                             endAngle:DEGREES_TO_RADIANS(115)
                            clockwise:NO];


self.plane = [CALayer layer];
self.plane.bounds = CGRectMake(0, 0, 60.0, 60.0);
self.plane.position = CGPointMake(self.scrollView.center.x,self.scrollView.center.y-20);
self.plane.contents = (id)([UIImage imageNamed:@"profile_tag"].CGImage);
[self.view.layer addSublayer:self.plane];

CAKeyframeAnimation *anim = [CAKeyframeAnimation animationWithKeyPath:@"position"];
anim.path = self.trackPath.CGPath;
anim.duration = 320.;
[self.plane addAnimation:anim forKey:nil];
self.plane.speed = 0.0;
self.plane.hidden = YES;

分页时：

- (void)scrollViewDidScroll:(UIScrollView *)scrollView {
    CGFloat pageWidth = self.scrollView.frame.size.width;
    int page = floor((self.scrollView.contentOffset.x - pageWidth / 2) / pageWidth) + 1;
    self.pageControl.currentPage = page;

    if((scrollView.contentOffset.x >= 320) && (scrollView.contentOffset.x<=640)){
        self.plane.hidden = NO;
        self.plane.timeOffset = scrollView.contentOffset.x - 320;
    }
}

用手势动画图像

1 个答案: