ios 关于截图

/** *  全屏截图 * */+(UIImage *)fullScreenshots{    UIWindow *screenWindow = [[UIApplication sharedApplication] keyWindow];    UIGraphicsBeginImageContext(screenWindow.frame.size);    [screenWindow.layer renderInContext:UIGraphicsGetCurrentContext()];    UIImage *viewImage = UIGraphicsGetImageFromCurrentImageContext();    UIGraphicsEndImageContext();    return viewImage;}/** *  scrollView截图，长截图 * */+(UIImage *)captureScrollView:(UIScrollView *)scrollView{    UIImage* image = nil;    UIGraphicsBeginImageContext(scrollView.contentSize);    {        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;}