问题描述
我在 UIScrollView 中有一张图片,可以滚动和缩放.
I have an image in an UIScrollView, that can be scrolled and zoomed.
当用户按下按钮时,我希望代码从我用 CGRect 指定的区域内的 UIScrollView 的任何部分创建图像.
When the user presses a button, I want the code to create an image from whatever part of the UIScrollView is inside an area I specify with a CGRect.
我见过裁剪 UIImages 的代码,但我无法调整它来为视图做同样的事情,因为它使用 CGContextDrawImage.
I've seen code to crop UIImages, but I can't adapt it to do the same for a view, because it uses CGContextDrawImage.
有什么想法吗?
干杯,安德烈
推荐答案
我已经搞定了.
这是我的解决方案,基于网络上的几个不同的解决方案:
Here's my solution, based on a few different ones from the web:
- (UIImage *)imageByCropping:(UIScrollView *)imageToCrop toRect:(CGRect)rect { CGSize pageSize = rect.size; UIGraphicsBeginImageContext(pageSize); CGContextRef resizedContext = UIGraphicsGetCurrentContext(); CGContextTranslateCTM(resizedContext, -imageToCrop.contentOffset.x, -imageToCrop.contentOffset.y); [imageToCrop.layer renderInContext:resizedContext]; UIImage *image = UIGraphicsGetImageFromCurrentImageContext(); UIGraphicsEndImageContext(); return image; }
您使用以下方式调用:
CGRect clippedRect = CGRectMake(0, 0, 320, 300); picture.image = [self imageByCropping:myScrollView toRect:clippedRect];