Question

我有一个UIView，我正在绘制一些东西--drawRect：。现在我需要来自这个图形上下文或UIView位图的CGImageRef。是否有一种简单的方法可以实现这一目标？

Answer 1

像这样（从内存中输入，因此可能不是100％正确）：

// Get a UIImage from the view's contents
UIGraphicsBeginImageContextWithOptions(view.bounds.size, view.opaque, view.contentScaleFactor);
CGContextRef context = UIGraphicsGetCurrentContext();
[view.layer renderInContext:context];
UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();

// Convert UIImage to CGImage
CGImageRef cgImage = image.CGImage;

Answer 2

还要确保添加

#import <QuartzCore/QuartzCore.h>

代码

Answer 3

快速5

extension UIView {
    var cgImage: CGImage? {
        guard bounds.size.width > 0 && bounds.size.height > 0 else {return nil}
        UIGraphicsBeginImageContextWithOptions(bounds.size, isOpaque, contentScaleFactor)
        layer.render(in: UIGraphicsGetCurrentContext()!)
        defer {UIGraphicsEndImageContext()}
        return UIGraphicsGetImageFromCurrentImageContext()!.cgImage!
    }
}

如何从UIView的内容中获取CGImageRef？

3 个答案: