在快照中捕获整个 tableview 单元格范围以进行打印和共享

Question

我正在尝试对整个滚动视图进行快照，“滚动视图”是一个表格视图，它是一个电子表格视图窗格。 SpreadsheetView 实际上是一个滚动视图/表格视图。我设置它的方式是 dequereusablecell。真的，我不知道任何其他方式，因为我对这一切都很陌生。问题是这会导致图像仅在保存的快照图像的一部分上呈现。

如何捕获整个电子表格视图/表格视图？

我已经搜索和搜索，但没有找到任何我可以理解或调整的结论性方法...

分享功能：

// Share function for share button
@objc func shareTapped() {
    
    UIGraphicsBeginImageContext(spreadsheetView.contentSize)

    let savedContentOffset = spreadsheetView.contentOffset
    let savedFrame = spreadsheetView.frame

    spreadsheetView.contentOffset = CGPoint.zero
    spreadsheetView.frame = CGRect(x: 0, y: 0, width: spreadsheetView.contentSize.width, height: spreadsheetView.contentSize.height)

    spreadsheetView.layer.render(in: UIGraphicsGetCurrentContext()!)
    let image = UIGraphicsGetImageFromCurrentImageContext()

    spreadsheetView.contentOffset = savedContentOffset
    spreadsheetView.frame = savedFrame

    UIGraphicsEndImageContext()
    
    // Give sharing functionality
    let vc = UIActivityViewController(activityItems: [image!], applicationActivities: [])
    vc.excludedActivityTypes = [.assignToContact, .addToReadingList]
    vc.popoverPresentationController?.barButtonItem = navigationItem.rightBarButtonItem
    present(vc, animated: true)
    
}

电子表格视图设置：

// First initialize column and row headers & add grid data
func spreadsheetView(_ spreadsheetView: SpreadsheetView, cellForItemAt indexPath: IndexPath) -> Cell? {
    let cell = spreadsheetView.dequeueReusableCell(withReuseIdentifier: CellStyle.identifier, for: indexPath) as! CellStyle
    cell.printable(with: "0")
    cell.backgroundColor = .white
    if case 0 = indexPath.row {
        cell.printable(with: columnHeaders[indexPath.section])
        return cell
    } else if case 0 = indexPath.section {
        cell.printable(with: rowHeaders[indexPath.row])
        return cell
// Spreadsheet setup
func numberOfColumns(in spreadsheetView: SpreadsheetView) -> Int {
    columnHeaders.count }
func numberOfRows(in spreadsheetView: SpreadsheetView) -> Int {
    rowHeaders.count }
func spreadsheetView(_ spreadsheetView: SpreadsheetView, widthForColumn column: Int) -> CGFloat {
    if case 0 = column {
        return 90
    } else {
        return 60
    }
}
func spreadsheetView(_ spreadsheetView: SpreadsheetView, heightForRow row: Int) -> CGFloat {
    18  }
func frozenColumns(in spreadsheetView: SpreadsheetView) -> Int {
    1   }
func frozenRows(in spreadsheetView: SpreadsheetView) -> Int {
    1   }

编辑：这也不起作用：

UIGraphicsBeginImageContextWithOptions(spreadsheetView.contentSize, false, UIScreen.main.scale)

    for section in 0..<spreadsheetView.numberOfColumns {
        for row in 0..<spreadsheetView.numberOfRows {
            let indexPath = IndexPath(row: row, section: section)
            guard let cell = spreadsheetView.cellForItem(at: indexPath) else { continue }
            cell.contentView.drawHierarchy(in: cell.frame, afterScreenUpdates: true)
        }
    }
    let image = UIGraphicsGetImageFromCurrentImageContext()
    UIGraphicsEndImageContext()

Answer 1

由于UITableView 仅呈现可见单元格，您可以尝试创建一个与其内容具有相同框架的新表格视图，以便所有单元格都可见，但我不确定这会对性能造成多大影响。您也可以在 UIView 中构建自己的“电子表格”并对其进行快照。