iPhone CALayer 图像数组内容值

发布于 2024-10-15 01:47:35 字数 656 浏览 7 评论 0原文

将图像加载到图层的方法很简单：

CALayer *layer = [[CALayer alloc]init];

layer.contents = (id) [UIImage imageNamed:@"image.png"].CGImage;

然后将图层作为子图层添加到视图中，如下所示：

假设您在视图中

[self.layer addSublayer:layer];

现在我想加载图像数组作为动画，所以最终我将使图像动画化。

因此，在实际执行动画之前，我测试了以下内容：

[values insertObject:(id)[UIImage imageNamed:path].CGImage atIndex:i];

当然，有一个运行的循环将每个图像输入到正确的索引...然后我得到一个 CGImage 数组..对于动画。

我已经打印了这个数组并看到了这个：

CGImage 0x17d900

CGImage 0x17f4e0

所以这些值就在那里..并且我没有收到任何错误..但我没有看到图像...

如果您有想法，请告诉我...

原文

The way to load image to the layer is simply this:

CALayer *layer = [[CALayer alloc]init];

layer.contents = (id) [UIImage imageNamed:@"image.png"].CGImage;

then you add the layer as sublayer to the view something like:

assume you in the view

[self.layer addSublayer:layer];

Now I want to load an array of image as animation so eventually I will get the images animated.

so before actually perform the animation I have tested the following:

[values insertObject:(id)[UIImage imageNamed:path].CGImage atIndex:i];

of course there is a loop that that runs that enter each image to the right index... and then I am getting an array of CGImage .. for the animation.

I have printed this array and saw this:

CGImage 0x17d900

CGImage 0x17f4e0

So the values are there.. and I am not getting any errors .. but I do not see the images...

Let me know if you have an idea ....

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追星践月 2024-10-22 01:47:35

这是一段代码片段，对于我的一个项目来说效果很好：

CAKeyframeAnimation *animation = [CAKeyframeAnimation animationWithKeyPath: @"contents"];
animation.calculationMode = kCAAnimationDiscrete;
animation.duration = 1.0;
animation.values = values; // NSArray of CGImageRefs
[layer addAnimation: animation forKey: @"contents"];

但是，我的动画帧和旧 iPhone/iPod 上的图像较大，这导致了严重的性能问题。如果您遇到这种情况，秘诀就是使用预渲染图像（IIRC，它们用私有 CABackingStore 类表示）。简而言之，您创建一个正确大小的 CALayer，它使用 drawInContext: 绘制单个动画帧，然后循环遍历动画帧，在其中向图层提供帧图像，将其发送display 并将其内容属性保存到数组中。只要您不尝试以任何方式操作预渲染图像，缓存技术就是安全的：基本上，您只需执行layer1.contents = layer2.contents即可。

除非确实存在性能问题，否则不要浪费时间实现上述内容。

This is a code snippet which worked fine for one of my projects:

CAKeyframeAnimation *animation = [CAKeyframeAnimation animationWithKeyPath: @"contents"];
animation.calculationMode = kCAAnimationDiscrete;
animation.duration = 1.0;
animation.values = values; // NSArray of CGImageRefs
[layer addAnimation: animation forKey: @"contents"];

However, I had largish images for animation frames and on old iPhones/iPods that caused serious performance problems. If you run into this, the secret ingredient is to use the pre-rendered images (IIRC, they are represented with a private CABackingStore class). In a nutshell, you make a CALayer of the correct size, which uses drawInContext: to draw a single animation frame, then you loop through the animation frames, where you feed the layer a frame image, send it display and save its contents property into an array. The caching technique is safe as long as you don't try to manipulate the pre-rendered images in any way: basically, you simply do layer1.contents = layer2.contents.

Just don't waste your time implementing the above unless you do have performance problems.

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