iOS开发屏幕截屏，超出屏幕截屏处理

/// 根据一个View生成一个image

+ (UIImage *)imageFromSnapShotView:(UIView *)view {

    UIImage *image = nil;

    if ([view.class isSubclassOfClass:[UIScrollView class]]) {

        UIScrollView *scroolView = (UIScrollView *)view;

        CGPoint tempContentOffset = scroolView.contentOffset;

        CGRect tempFrame = scroolView.frame;

        scroolView.contentOffset = CGPointZero;

        scroolView.frame = CGRectMake(0, 0, scroolView.contentSize.width, scroolView.contentSize.height);

        image = [UIImage screenshotForView:scroolView size:scroolView.frame.size];

        scroolView.contentOffset = tempContentOffset;

        scroolView.frame = tempFrame;

    } else {

        image = [UIImage screenshotForView:view size:view.frame.size];

    }

//    return image;

    return [UIImage imageWithData:UIImageJPEGRepresentation(image, 1.0f) scale:0.2];

}

+ (UIImage *)screenshotForView:(UIView *)view size:(CGSize)size {

    UIImage *image = nil;

    UIGraphicsBeginImageContextWithOptions(size, YES, [UIScreen mainScreen].scale);

    [view.layer renderInContext:UIGraphicsGetCurrentContext()];

    image = UIGraphicsGetImageFromCurrentImageContext();

    UIGraphicsEndImageContext();

    return image;

}