Ios 如何在Swift中拍摄UITableView中选定行的屏幕截图并将其保存为UIImage？

在我的

Swift

应用程序中，我有一个

UITableView

，它包含4个静态单元格，然后有不同数量的动态单元格。我只想拍一张静态单元格的截图

我找到了以下扩展：

extension UITableView {
    var capturedImage : UIImage {
        UIGraphicsBeginImageContext(contentSize);
        scrollToRow(at: NSIndexPath(row: 0, section: 0) as IndexPath, at:     UITableViewScrollPosition.top, animated: false)
        layer.render(in: UIGraphicsGetCurrentContext()!)
        let row = numberOfRows(inSection: 0)
        let numberofRowthatShowinscreen = 4
        let scrollCount = row / numberofRowthatShowinscreen

        for i in 0 ..< scrollCount  {
            scrollToRow(at: NSIndexPath(row: (i+1)*numberofRowthatShowinscreen, section: 0) as     IndexPath, at: UITableViewScrollPosition.top, animated: false)
            layer.render(in: UIGraphicsGetCurrentContext()!)
        }

        let image:UIImage = UIGraphicsGetImageFromCurrentImageContext()!
        UIGraphicsEndImageContext();
        return image;
    }
}

致：

---

然后它仍然需要整个

UITableView

的屏幕截图。是否有办法将其限制为仅前4行？

在示例代码中，您正在图像上下文中呈现表视图的层。这将始终快照整个表视图。您可以采纳评论者的建议，在对表视图进行快照之前调整其单元格。或者，可以快照要渲染的单元的层。例如：

extension UITableView
{
    func snapshotRows(at indexPaths: Set<IndexPath>) -> UIImage?
    {
        guard !indexPaths.isEmpty else { return nil }
        var rect = self.rectForRow(at: indexPaths.first!)
        for indexPath in indexPaths
        {
            let cellRect = self.rectForRow(at: indexPath)
            rect = rect.union(cellRect)
        }

        UIGraphicsBeginImageContextWithOptions(rect.size, false, 0.0)
        guard let context = UIGraphicsGetCurrentContext() else { return nil }
        for indexPath in indexPaths
        {
            let cell = self.cellForRow(at: indexPath)
            cell?.layer.bounds.origin.y = self.rectForRow(at: indexPath).origin.y - rect.minY
            cell?.layer.render(in: context)
            cell?.layer.bounds.origin.y = 0
        }

        let image = UIGraphicsGetImageFromCurrentImageContext()
        UIGraphicsEndImageContext()
        return image
    }
}

---

将仅快照特定的单元格。正如另一篇文章的答案所说，这只适用于重复使用单元格的可见单元格。

为什么不简单地控制返回数据源的表视图数据源数组。在调用CaptureDimage之前，前缀（4）此方法在iOS 13中不适用于动态高度单元格。

let numberofRowthatShowinscreen = 3

extension UITableView
{
    func snapshotRows(at indexPaths: Set<IndexPath>) -> UIImage?
    {
        guard !indexPaths.isEmpty else { return nil }
        var rect = self.rectForRow(at: indexPaths.first!)
        for indexPath in indexPaths
        {
            let cellRect = self.rectForRow(at: indexPath)
            rect = rect.union(cellRect)
        }

        UIGraphicsBeginImageContextWithOptions(rect.size, false, 0.0)
        guard let context = UIGraphicsGetCurrentContext() else { return nil }
        for indexPath in indexPaths
        {
            let cell = self.cellForRow(at: indexPath)
            cell?.layer.bounds.origin.y = self.rectForRow(at: indexPath).origin.y - rect.minY
            cell?.layer.render(in: context)
            cell?.layer.bounds.origin.y = 0
        }

        let image = UIGraphicsGetImageFromCurrentImageContext()
        UIGraphicsEndImageContext()
        return image
    }
}

let image = tableView.snapshotRows(at: Set([IndexPath(row: 0, section: 0), IndexPath(row: 0, section: 1)]))