iOS 截图

- (UIImage *)captureScrollView:(UIScrollView *)scrollView{    UIImage* image = nil;    UIGraphicsBeginImageContextWithOptions(scrollView.contentSize, NO, 0.0);    {        CGPoint savedContentOffset = scrollView.contentOffset;        CGRect savedFrame = scrollView.frame;        scrollView.contentOffset = CGPointZero;        scrollView.frame = CGRectMake(0, 0, scrollView.contentSize.width, scrollView.contentSize.height);        [scrollView.layer renderInContext: UIGraphicsGetCurrentContext()];        image = UIGraphicsGetImageFromCurrentImageContext();        scrollView.contentOffset = savedContentOffset;        scrollView.frame = savedFrame;    }    UIGraphicsEndImageContext();    if (image != nil) {        return image;    }    return nil;}