自定义“可调整大小的图像”在iOS中绘图 [英] Custom "resizable image" drawing in iOS

问题描述

UIImage API提供了以某些区域被拉伸的方式调整图像大小的方法，而其他区域保持不变 - 非常适合可调整大小的UI元素的背景图像。

The UIImage API provides methods to resize an image in a way that certain areas get stretched, while others remain unaltered - great for background images for resizable UI elements.

现在我正在寻找一种方法来为更复杂的背景图像自定义此行为。

Now I am looking for a way to customize this behavior for more complex background images.

这是 - （UIImage *）resizableImageWithCapInsets：（UIEdgeInsets）capInsets; 的确如此。透明区域保持不变，当视图大小改变时，红色区域会被拉伸。

This is what - (UIImage *)resizableImageWithCapInsets:(UIEdgeInsets)capInsets; does. The transparent areas remain unaltered, the red areas are stretched when the view size is changed.

这就是我想要的 - 对拉伸区域进行更精细的控制：

This is what i want - finer grained control over the areas that are stretched:

我想我必须通过覆盖我的UIView子类的 - （void）drawRect：方法然后使用Quartz来绘制图片。

I guess I'd have to do that by overwriting the -(void)drawRect: method of my UIView subclass and then use Quartz to do the drawing of the image.

我无法弄清楚我必须使用哪种系统API。

I just can't figure out which of the system APIs I would have to use.

有人能给我一个提示如何实现这个目标吗？
提前致谢！

Could anybody give me a hint how to accomplish this? Thanks in advance!

推荐答案

我只想在里面使用三个独立的UIImageViews和resizableImageWithCapInsets。您也可以在drawRect中使用，例如，CGPattern，但在缩放视图时会出现性能问题。

I would just use three separate UIImageViews with resizableImageWithCapInsets inside. You could also so it in drawRect using, for example, CGPattern, but you would have performance issue when scaling the view.

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