问题描述
我一直在尝试使用CALayer为圆形绘图添加动画效果。这一切都运作良好，但问题是 - 绘制圆圈不足以抗锯齿。它有一个太粗糙的边框，（如果使用栅格化，则会模糊）。 （已启用AntiAliasing）
I've been trying to animate circle drawing using CALayer. It all works well, but the problem is - drawn circle is not antialiased enough. It has a bit too rough borders, (or blurred if rasterize is used). (AntiAliasing is enabled)
还尝试：
无济于事。
以下是一个例子如何看似没有光栅化：
Here is an example how it looks like without rasterization:
以下是光栅化的示例:(尝试从1.0到4.0的值（只是为了确定。结果 - 相同。）
And here is an example with rasterization: (tried values from 1.0 till 4.0 (just to be sure. Result - the same.))
这是相同的圆圈，但是绘制在UIView内部：
And here is the same circle, but drawn inside UIView drawrect:
你可以看到，使用UIView drawrect绘制的圆圈看起来好多了。
You can see, that circle drawn using UIView drawrect is looking much better.
我无法使用的原因UIView是因为我需要为圆形填充动画。使用CALayer非常简单，但是在UIView上做同样的事情，我真的不知道它是否可能。 （我可以尝试启动drawrect：每1/60秒，但我认为它会变得迟钝，因为它不是那样的。）
The reason I cannot use UIView is because I need to animate circle filling. Using CALayer it is really easy, but to do the same on UIView, I don't really know if it is even possible. (I could try to launch drawrect: every 1/60 seconds, but I think it will get laggy, as it is not intended that way).
所以 - 有没有人有任何解决方案如何在CALayer上绘制圆圈/线条与UIView上绘制的相同？
推荐答案
我之前在视网膜设备上的 CALayer 中存在像素化绘图问题。 （我假设您在视网膜设备上看到了问题）执行以下操作修复了我遇到的问题：
I've had issues with pixelated drawing in a CALayer on retina devices before. (I'm assuming you're seeing the issue on retina devices) Doing the following fixed the issue I was experiencing:
layer.contentsScale = [[UIScreen mainScreen] scale];
您不需要处理光栅化或抗锯齿。在我自己的代码中，我最初实现了绘制到 UIView 的东西，后来我改为绘制在 CALayer 中，只需设置 contentsScale 属性，两者都相同。
You shouldn't need to deal with rasterization or antialiasing. In my own code, I had initially implemented drawing something to a UIView that I later changed to be drawn in a CALayer, and simply setting the contentsScale property made both draw identically.
这篇关于CALayer Antialiasing不如UIView抗锯齿的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！