xcode 如何从 UIView / UIScrollView 创建图像
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How to create an image from a UIView / UIScrollView
提问by Andre
I have an image in an UIScrollView, that can be scrolled and zoomed.
我在 UIScrollView 中有一个图像，可以滚动和缩放。
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.
当用户按下按钮时，我希望代码从 UIScrollView 的任何部分创建一个图像，该部分位于我用 CGRect 指定的区域内。
I've seen code to crop UIImages, but I can't adapt it to do the same for a view, because it uses CGContextDrawImage.
我已经看到裁剪 UIImages 的代码，但我无法对其进行修改以对视图执行相同的操作，因为它使用了 CGContextDrawImage。
Any thoughts?
有什么想法吗？
Cheers, Andre
干杯，安德烈
回答by Andre
I've managed to get it.
我设法得到了它。
Here's my solution, based on a few different ones from the web:
这是我的解决方案，基于网络上的一些不同解决方案：
- (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;
}
which you call by using:
您可以使用以下方法调用：
CGRect clippedRect = CGRectMake(0, 0, 320, 300);
picture.image = [self imageByCropping:myScrollView toRect:clippedRect];
