当我创建一个显式动画来将CAShapeLayer的路径值从椭圆更改为矩形时,我遇到了一个问题.
在我的画布控制器中,我设置了一个基本的CAShapeLayer并将其添加到根视图的图层：
- CAShapeLayer *aLayer;
- aLayer = [CAShapeLayer layer];
- aLayer.frame = CGRectMake(100,100,100);
- aLayer.path = CGPathCreateWithEllipseInRect(aLayer.frame,nil);
- aLayer.lineWidth = 10.0f;
- aLayer.strokeColor = [UIColor blackColor].CGColor;
- aLayer.fillColor = [UIColor clearColor].CGColor;
- [self.view.layer addSublayer:aLayer];
然后,当我为路径设置动画时,在动画的最后几帧中,当形状变为矩形时会出现奇怪的毛刺/闪烁,而在前几帧中,当动画远离矩形时,会出现奇怪的毛刺/闪烁.动画设置如下：
- CGPathRef newPath = CGPathCreateWithRect(aLayer.frame,nil);
- [CATransaction lock];
- [CATransaction begin];
- [CATransaction setAnimationDuration:5.0f];
- CABasicAnimation *ba = [CABasicAnimation animationWithKeyPath:@"path"];
- ba.autoreverses = YES;
- ba.fillMode = kCAFillModeForwards;
- ba.repeatCount = HUGE_VALF;
- ba.fromValue = (id)aLayer.path;
- ba.toValue = (__bridge id)newPath;
- [aLayer addAnimation:ba forKey:@"animatePath"];
- [CATransaction commit];
- [CATransaction unlock];
我尝试了很多不同的东西,比如锁定/解锁CATransaction,玩各种填充模式等等……
这是故障的图像：
http://www.postfl.com/outgoing/renderingglitch.png
可以在此处找到我正在体验的视频：
http://vimeo.com/37720876
