Programmatically reordering a table view on macOS using drag and drop. A full example in this Playground, with setup and tear down code. For a detailed guide to how this works, see: https://kitcross.net/reorder-table-views-drag-drop/

ReorderTableView.swift

import Cocoa
import PlaygroundSupport

class BackgroundView: NSView {
  override func draw(_ dirtyRect: NSRect) {
    NSColor.underPageBackgroundColor.set()
    dirtyRect.fill()
  }
}

class ReorderTableViewController: NSViewController {

  // Our data source. It’s important this is an array
  // so we can rearrange it later on after a drop
  var accounts: [String] = {
    var array: [String] = []
    array.append(contentsOf: ["[email protected]", "[email protected]", "[email protected]", "[email protected]", "[email protected]"])
    return array
  }()

  let tableView: NSTableView = {
    let tableView = NSTableView()
    tableView.usesAlternatingRowBackgroundColors = true
    tableView.allowsColumnReordering = false
    tableView.allowsColumnResizing = false
    return tableView
  }()

  let scrollView = NSScrollView()

  override func loadView() {
    view = BackgroundView()
  }

  override func viewDidLoad() {
    super.viewDidLoad()

    tableView.registerForDraggedTypes([.string])

    let emailColumn = NSTableColumn()
    emailColumn.title = "E-mail address"
    emailColumn.width = 230

    tableView.delegate = self
    tableView.dataSource = self

    tableView.addTableColumn(emailColumn)

    scrollView.documentView = tableView
    scrollView.frame = NSRect(x: 20, y: 20, width: 400, height: 200)
    scrollView.borderType = .lineBorder

    view.addSubview(scrollView)
  }
}

extension ReorderTableViewController: NSTableViewDelegate {
  func tableView(_ tableView: NSTableView, heightOfRow row: Int) -> CGFloat {
    return 30
  }
}

extension ReorderTableViewController: NSTableViewDataSource {
  func tableView(_ tableView: NSTableView, pasteboardWriterForRow row: Int) -> NSPasteboardWriting? {
    return accounts[row] as NSString
  }

  func tableView(_ tableView: NSTableView, validateDrop info: NSDraggingInfo, proposedRow row: Int, proposedDropOperation dropOperation: NSTableView.DropOperation) -> NSDragOperation {

    guard dropOperation == .above,
          let tableView = info.draggingSource as? NSTableView else { return [] }

    tableView.draggingDestinationFeedbackStyle = .gap
    return .move
  }

  func tableView(_ tableView: NSTableView, acceptDrop info: NSDraggingInfo, row: Int, dropOperation: NSTableView.DropOperation) -> Bool {

    /* Read the pasteboard items and ensure there is at least one item,
     find the string of the first pasteboard item and search the datasource
     for the index of the matching string */
    guard let items = info.draggingPasteboard.pasteboardItems,
          let pasteBoardItem = items.first,
          let pasteBoardItemName = pasteBoardItem.string(forType: .string),
          let index = accounts.firstIndex(of: pasteBoardItemName) else { return false }

    let indexset = IndexSet(integer: index)
    accounts.move(fromOffsets: indexset, toOffset: row)

    /* Animate the move to the rows in the table view. The ternary operator
     is needed because dragging a row downwards means the row number is 1 less */
    tableView.beginUpdates()
    tableView.moveRow(at: index, to: (index < row ? row - 1 : row))
    tableView.endUpdates()

    return true
  }

  func tableView(_ tableView: NSTableView, viewFor tableColumn: NSTableColumn?, row: Int) -> NSView? {
    let view = NSView()
    let account = accounts[row]

    let emailTextField = NSTextField(labelWithString: account)
    emailTextField.frame = NSRect(x: 0, y: 7, width: 200, height: 16)
    view.addSubview(emailTextField)

    return view
  }

  func numberOfRows(in tableView: NSTableView) -> Int {
    return accounts.count
  }

}

let vc = ReorderTableViewController(nibName: nil, bundle: nil)
vc.view.frame = NSRect(x: 0, y: 0, width: 440, height: 240)

PlaygroundPage.current.liveView = vc

Thanks, resolve my problem.