问iOS 11拖放UIDocument

EN

func tableView(_ tableView: UITableView, itemsForBeginning session: UIDragSession, at indexPath: IndexPath) -> [UIDragItem] {

    let doc = DataManager.shared.storage[indexPath.row] // the UIDocument to drag
    let itemProv = NSItemProvider()
    itemProv.registerFileRepresentation(forTypeIdentifier: "com.mybundle.myapp.myextension",
                                        fileOptions: [.openInPlace],
                                        visibility: .all) { completionHandler in

        completionHandler(doc.fileURL, true, nil)
        return nil
    }

    // DragItem
    let item = UIDragItem(itemProvider: itemProv)

    return [item]
}

func tableView(_ tableView: UITableView, performDropWith coordinator: UITableViewDropCoordinator) {

    for item in coordinator.session.items {
        item.itemProvider.loadFileRepresentation(forTypeIdentifier: "com.mybundle.myapp.myextension", completionHandler: { (url, error) in

            if let docUrlOk = url {
                debugPrint(urlOk.absoluteString)
                DataManager.shared.load(docUrlOk)
            }
        })
    }
}

func tableView(_ tableView: UITableView, dropSessionDidUpdate session: UIDropSession, withDestinationIndexPath destinationIndexPath: IndexPath?) -> UITableViewDropProposal {

    if tableView.hasActiveDrag {
        if session.items.count > 1 {
            return UITableViewDropProposal(operation: .cancel)
        } else {
            return UITableViewDropProposal(operation: .move, intent: .insertAtDestinationIndexPath)
        }
    } else {
        return UITableViewDropProposal(operation: .copy, intent: .insertAtDestinationIndexPath)
    }
}