iOS 获取一整屏的截图

具体实现代码：

-(UIImage *)getTableViewimage{
    UIImage* viewImage = nil;
    UITableView *scrollView = self.tableView;
    UIGraphicsBeginImageContextWithOptions(scrollView.contentSize, scrollView.opaque, 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()];
        viewImage = UIGraphicsGetImageFromCurrentImageContext();
 
        scrollView.contentOffset = savedContentOffset;
        scrollView.frame = savedFrame;
    }
    UIGraphicsEndImageContext();
 
    return viewImage;
}