即使我按顺序删除，部分中的行数也无效

问题描述

我有一个 tableView，用户可以在其中删除 cells.这是在 cellForRowAt 中的 class WhishlistTableViewController: UITableViewController:

I have a tableView in which the user can delete cells. This is in cellForRowAt in class WhishlistTableViewController: UITableViewController:

cell.deleteWishCallback = { [unowned self] deletedCell in
    print("delete with callback")
    guard let indexPath = tableView.indexPath(for: deletedCell) else { return }
    self.deleteWishDelegate?.deleteWish(indexPath, currentWish.wishCounter)
    self.wishData.remove(at: indexPath.row)
    tableView.deleteRows(at: [indexPath], with: .right)
    print("removed from tableView")
}

但我仍然使用 delegate 从数据库中删除 Wish 以及从 ViewController 内的主要 datasourceArray 这样我就可以将它安全地保存到 UserDefaults:

But I am still using the delegate to remove the Wish from the database and also from my main datasourceArray inside the ViewController so I can safe it to UserDefaults:

extension WishlistViewController: DeleteWishDelegate {
    func deleteWish(_ idx: IndexPath, _ wishCounter: Int){
        // remove the wish from the user's currently selected wishlist
        print("delete2")
        self.dataSourceArray[currentWishListIDX].wishes.remove(at: idx.row)
        if let defaults = UserDefaults(suiteName: UserDefaults.Keys.groupKey) {
            defaults.setDataSourceArray(data: self.dataSourceArray)
            defaults.synchronize()
        } else {
            print("error")
        }
        DataHandler.deleteWish(wishCounter, self.dataSourceArray[currentWishListIDX].name)
    }
}

但是，如果我删除 cells 并再次添加，则会导致错误:

However this causes an error if I delete cells and add again:

'无效更新:第 0 节中的行数无效.更新后现有节中包含的行数 (5) 必须等于更新前该节中包含的行数 (2)，加上或减去从该部分插入或删除的行数(插入 1 行，删除 0 行)，加上或减去移入或移出该部分的行数(0 移入，0 移出).'

我搜索了那个，当你没有按正确的顺序删除时，这通常会触发，但我认为我是按照正确的方式做的?(首先来自 tableViewData(wishData)，然后来自 tableView 本身和 deleteRows.我在这里遗漏了什么?

I searched for that and this usually fire when you don't delete in the right order but I thought I am doing it the right way? (first from the tableViewData(wishData) and then from the tableView itself with deleteRows. What am I missing here?

顺便说一下，删除 cell 时，这是 print-statements 的顺序:

By the way when deleting a cell this is the order of the print-statements:

使用回调删除

删除2

行数:2

从 tableView 中移除

removed from tableView

更新:

正如评论中所建议的，问题可能在于我如何添加 cells.我就是这样做的:

As suggested in the comments, the problem might be in how I add cells. This is how I do that:

func addWishComplete(wishName: String, selectedWishlistIDX: Int, wishImage: UIImage?, wishLink: String?, wishPrice: String?, wishNote: String?, wishCounter: Int?) {

    let wishToAdd = Wish(name: wishName, link: wishLink!, price: wishPrice!, note: wishNote!, image: wishImage!, checkedStatus: false, wishCounter: wishCounter!)

    self.dataSourceArray[selectedWishlistIDX].wishes.append(wishToAdd)
    DataHandler.saveWish(dataSourceArray: self.dataSourceArray, selectedWishlistIdx: selectedWishlistIDX, wish: wishToAdd)
    // save dataSourceArray with new wish in UserDefaults
    if let defaults = UserDefaults(suiteName: UserDefaults.Keys.groupKey) {
        defaults.setDataSourceArray(data: self.dataSourceArray)
        defaults.synchronize()
    } else {
        print("error wish to datasource")
    }

    // only update current list if selectedWishlist is currentWishlist
    if selectedWishlistIDX == currentWishListIDX {
        wishList.wishes.append(Wish(name: wishName, link: wishLink!, price: wishPrice!, note: wishNote!, image: wishImage!, checkedStatus: false, wishCounter: wishCounter!))

        theTableView.wishData = wishList.wishes
        theTableView.tableView.beginUpdates()
        theTableView.tableView.insertRows(at: [
            (NSIndexPath(row: theTableView.wishData.count-1, section: 0) as IndexPath)], with: .left)
        theTableView.tableView.endUpdates()
    }
    dismissWishView()
}

推荐答案

我发现了问题.正如评论中已经提到的，我必须可以直接在 wishData 上工作以 remove :

I found the problem. As already mentioned in the comments I have to can work directly on wishData to remove :

func addWishComplete(wishName: String, selectedWishlistIDX: Int, wishImage: UIImage?, wishLink: String?, wishPrice: String?, wishNote: String?, wishCounter: Int?) {

    let wishToAdd = Wish(name: wishName, link: wishLink!, price: wishPrice!, note: wishNote!, image: wishImage!, checkedStatus: false, wishCounter: wishCounter!)

    self.dataSourceArray[selectedWishlistIDX].wishes.append(wishToAdd)
    DataHandler.saveWish(dataSourceArray: self.dataSourceArray, selectedWishlistIdx: selectedWishlistIDX, wish: wishToAdd)
    // save dataSourceArray with new wish in UserDefaults
    if let defaults = UserDefaults(suiteName: UserDefaults.Keys.groupKey) {
        defaults.setDataSourceArray(data: self.dataSourceArray)
        defaults.synchronize()
    } else {
        print("error wish to datasource")
    }

    // only update current list if selectedWishlist is currentWishlist
    if selectedWishlistIDX == currentWishListIDX {
        wishList.wishes.append(wishToAdd)

        theTableView.wishData.append(wishToAdd)
        theTableView.tableView.beginUpdates()
        theTableView.tableView.insertRows(at: [
            (NSIndexPath(row: theTableView.wishData.count-1, section: 0) as IndexPath)], with: .left)
        theTableView.tableView.endUpdates()
    }
    dismissWishView()
}

感谢大家的帮助！

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