iOS截图

1.普通的截图办法，在View上面截图

/**
 *  截图代码
 *
 *  @param view 需要截图的view
 *  @param rect 需要截取的区域
 *
 *  @return 返回截取的对象
 */
+ (UIImage *)viewSnapshot:(UIView *)view withInRect:(CGRect)rect
{

    UIGraphicsBeginImageContext(view.bounds.size);
    [view.layer renderInContext:UIGraphicsGetCurrentContext()];
    UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();
    CGImageRef imageRef = CGImageCreateWithImageInRect(image.CGImage,rect);
    image = [UIImage imageWithCGImage:imageRef];
    CGImageRelease(imageRef);
    return image;
}

2.截取UIScrollView的ContentSize的全部区域，包括未显示的部分，将UIScrollView传递进去

/**
 *  UIScrollView从顶截到底
 *
 *  @param scrollView 需要呗截图的UIScrollView
 *
 *  @return 返回UIScrollView的ContentSize的截图
 */
+ (UIImage *)screenShot:(UIScrollView *)scrollView{
    UIImage *image = nil;
    UIGraphicsBeginImageContext(scrollView.contentSize);
    {
        CGPoint savedContentOffset = scrollView.contentOffset;
        CGRect savedFrame = scrollView.frame;
        scrollView.contentOffset = CGPointZero;
        scrollView.frame = CGRectMake(, , scrollView.contentSize.width, scrollView.contentSize.height);
        [scrollView.layer renderInContext:UIGraphicsGetCurrentContext()];
        image = UIGraphicsGetImageFromCurrentImageContext();
        scrollView.contentOffset = savedContentOffset;
        scrollView.frame = savedFrame;
    }
    UIGraphicsEndImageContext();

    if (image != nil) {
        NSLog(@"截图成功!");
    }

    return image;
}