如何获取UIScrollView可见区域的屏幕截图? [英] How to take screenshot of UIScrollView visible area?

问题描述

如何拍摄UIScrollView可见区域的1:1屏幕截图?内容可能大于或小于UIScrollView边界以及半隐藏(我已经为较小的内容实现了自定义滚动，因此它不在左上角). 我已经在模拟器上达到了预期的结果，但是在设备本身上却没有:

How do I take a 1:1 screenshot of UIScrollView visible area? The content may be larger or smaller than UIScrollView bounds as well as half-hidden (I've implemented custom scrolling for smaller content, so it's not in the top-left corner). I've achieved desired result on simulator, but not on device itself:

-(UIImage *)imageFromCombinedContext:(UIView *)background {
      UIImage *image;
      CGRect vis = background.bounds;
      CGSize size = vis.size;
      UIGraphicsBeginImageContext(size);
      [background.layer affineTransform];
      [background.layer renderInontext:UIGraphicsGetCurrentContext()];
      image = UIGraphicsGetImageFromCurrentImageContext();
      UIGraphicsEndImageContext();
      CGImageRef imref = CGImageCreateWithImageInRect([image CGImage], vis);
      image = [UIImage imageWithCGImage:imref];
      CGImageRelease(imref);
      return image;
}

推荐答案

我自己找到了一个解决方案-我拍摄了整个视图的屏幕截图，然后将其裁剪为UIScrollView帧的大小和位置.

I've found a solution myself - I took screenshot of the whole view and then crop it to the size and position of UIScrollView frame.

-(UIImage *)imageFromCombinedContext:(UIView *)background 
{
      UIImage *image;
      CGSize size = self.view.frame.size;
      UIGraphicsBeginImageContext(size);
      [background.layer affineTransform];
      [self.view.layer.layer renderInContext:UIGraphicsGetCurrentContext()];
      image = UIGraphicsGetImageFromCurrentImageContext();
      UIGraphicsEndImageContext();
      CGImageRef imgRef = CGImageCreateWithImageInRect([image CGImage],background.frame);
      image = [UIImage imageWithCGImage:imref];
      CGImageRelease(imref);
      return image;
}

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