iOS 截取tableView, scrollerView图片

    CGPoint currentOffset = self.storeTable.contentOffset;
    CGRect currentFrame =self.storeTable.frame;
    self.storeTable.contentOffset = CGPointZero;
    // 2. 将 scrollView 展开为其实际内容的大小
    self.storeTable.frame=CGRectMake(0,0,self.storeTable.contentSize.width,  3*325);
    // 3. 第三个参数设置为 0 表示设置为屏幕的默认缩放因子
    UIGraphicsBeginImageContextWithOptions(CGSizeMake(SCREEN_WIDTH, 3 * 325), YES, 0);
    self.storeTable.layer.backgroundColor = [UIColor whiteColor].CGColor;
    [self.storeTable.layer renderInContext:UIGraphicsGetCurrentContext()];
    UIImage *snapshotImage = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();
        // 保存到相册
    UIImageWriteToSavedPhotosAlbum(snapshotImage, nil, nil, nil); 
    // 4. 重新设置 scrollView 的偏移和位置，还原现场
    self.storeTable.contentOffset= currentOffset;
    self.storeTable.frame= currentFrame;