所以我试图从tableViewCell内部的tableView中删除项目。该应用程序几乎是一种“待办事项列表”类型的应用程序，用户可以在其中添加任务，然后将具有相同日期的任务分组到一起。
日期位于其自己的tableView中，并且在这些日期的单元格中包括位于其下的适当任务的tableView。
但是，每当我删除tableViewCell中的tableView中的任务时，应用程序就会崩溃。
我已经查找了删除行但没有更改时收到的错误。它们仅适用于普通的tableViews。不是tableViewCell中的tableViews。
我尝试添加tableView.beginUpdates()和tableView.endUpdates()，但问题仍然存在。我不确定下一步该怎么做，因为我认为这应该可行，而且我真的找不到在tableViewCell的tableView中删除行的很多信息。
下面的代码是
ToDoListTableViewController.swift（外部tableView）
class ToDoListTableViewController: UITableViewController {
// MARK: - Properties
var toDos = [ToDo]()
var toDoDateGroup = [String]()
var matchedToDoCount: Int = 0
//var savedToDos = [ToDo]()
override func viewDidLoad() {
super.viewDidLoad()
tableView.delegate = self
tableView.dataSource = self
// If there are saved ToDos, load them
if let savedToDos = loadToDos() {
toDos = savedToDos
}
groupToDosAccordingToDates()
sortToDoGroupDates()
}
override func viewWillAppear(_ animated: Bool) {
super.viewWillAppear(animated)
//savedToDos = loadToDos()!
groupToDosAccordingToDates()
sortToDoGroupDates()
reloadTableViewData()
}
// MARK: - Table view data source
override func numberOfSections(in tableView: UITableView) -> Int {
// #warning Incomplete implementation, return the number of sections
return 1
}
override func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
// #warning Incomplete implementation, return the number of rows
return toDoDateGroup.count
}
override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
// Table view cells are reused and should be dequeued using a cell identifier.
let dateCellIdentifier = "ToDoTableViewCell"
let dateFormatter = DateFormatter()
dateFormatter.dateFormat = "M/d/yy"
//dateFormatter.dateFormat = "M/d/yy, h:mm a"
guard let cell = tableView.dequeueReusableCell(withIdentifier: dateCellIdentifier, for: indexPath) as? ToDoTableViewCell else {
fatalError("The dequeued cell is not an instance of ToDoTableViewCell.")
}
// Fetches the appropriate toDo for the data source layout.
let toDoDate = toDoDateGroup[indexPath.row]
cell.toDoDate = dateFormatter.date(from: toDoDate)!
cell.toDoDateWeekDayLabel.text = toDoDate
cell.toDoDateWeekDayLabel.backgroundColor = UIColor.green
for toDo in toDos {
//print(dateFormatter.string(from: toDo.workDate))
//print("cell.ToDoDate Below:")
//print(toDoDate)
if dateFormatter.string(from: toDo.workDate) == toDoDate {
cell.toDos.append(toDo)
}
}
matchedToDoCount = cell.toDos.count
//cell.toDoTableView.reloadData()
return cell
}
override func tableView(_ tableView: UITableView, heightForRowAt indexPath: IndexPath) -> CGFloat {
return 150
}
// MARK: - Actions
@IBAction func unwindToToDoList(sender: UIStoryboardSegue) {
if let sourceViewController = sender.source as? ToDoItemTableViewController, let toDo = sourceViewController.toDo {
if let selectedIndexPath = tableView.indexPathForSelectedRow {
let dateFormatter = DateFormatter()
dateFormatter.dateFormat = "M/d/yy"
// Update an existing ToDo
//toDos.append(toDo)
toDoDateGroup[selectedIndexPath.row] = dateFormatter.string(from: toDo.workDate)
tableView.reloadRows(at: [selectedIndexPath], with: .none)
}
else {
// Add a new toDo
toDos.append(toDo)
var newIndexPath: IndexPath
let dateFormatter = DateFormatter()
dateFormatter.dateFormat = "M/d/yy"
if (toDoDateGroup.isEmpty) {
newIndexPath = IndexPath(row: toDoDateGroup.count, section: 0)
toDoDateGroup.append(dateFormatter.string(from: toDo.workDate))
tableView.insertRows(at: [newIndexPath], with: .automatic)
} else {
groupToDosAccordingToDates()
}
}
// Save the ToDos
saveToDos()
}
}
// Override to support conditional editing of the table view.
override func tableView(_ tableView: UITableView, canEditRowAt indexPath: IndexPath) -> Bool {
// Return false if you do not want the specified item to be editable.
return true
}
// MARK: - Navigation
// In a storyboard-based application, you will often want to do a little preparation before navigation
override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
super.prepare(for: segue, sender: sender)
switch(segue.identifier ?? "") {
case "AddToDoItem":
os_log("Adding a new ToDo item.", log: OSLog.default, type: .debug)
case "ShowToDoItemDetails":
guard let toDoItemDetailViewController = segue.destination as? ToDoItemTableViewController else {
fatalError("Unexpected destination: \(segue.destination)")
}
guard let selectedToDoItemCell = sender as? ToDoGroupTableViewCell else {
fatalError("Unexpected sender: \(sender)")
}
guard let indexPath = tableView.indexPath(for: selectedToDoItemCell) else {
fatalError("The selected cell is not being displayed by the table")
}
let selectedToDoItem = toDos[indexPath.row]
toDoItemDetailViewController.toDo = selectedToDoItem
default:
fatalError("Unexpected Segue Identifier; \(segue.identifier)")
}
}
// MARK: - Private Methods
private func saveToDos() {
//sortToDosByWorkDate()
let isSuccessfulSave = NSKeyedArchiver.archiveRootObject(toDos, toFile: ToDo.ArchiveURL.path)
if isSuccessfulSave {
os_log("ToDos successfully saved.", log: OSLog.default, type: .debug)
} else {
os_log("Failed to save toDos...", log: OSLog.default, type: .error)
}
}
private func loadToDos() -> [ToDo]? {
return NSKeyedUnarchiver.unarchiveObject(withFile: ToDo.ArchiveURL.path) as? [ToDo]
}
private func groupToDosAccordingToDates() {
let dateFormatter = DateFormatter()
dateFormatter.dateFormat = "M/d/yy"
//dateFormatter.dateFormat = "M/d/yy, h:mm a"
var newIndexPath: IndexPath
for toDo in toDos {
print(toDo.taskName)
let chosenWorkDate = dateFormatter.string(from: toDo.workDate)
if !toDoDateGroup.contains(chosenWorkDate) {
print(chosenWorkDate)
newIndexPath = IndexPath(row: toDoDateGroup.count, section: 0)
toDoDateGroup.append(chosenWorkDate)
tableView.insertRows(at: [newIndexPath], with: .automatic)
}
}
}
private func sortToDoGroupDates() {
toDoDateGroup = toDoDateGroup.sorted(by: {
$1 > $0
})
}
private func reloadTableViewData() {
DispatchQueue.main.async {
self.tableView.reloadData()
}
}
}
ToDoTableViewCell.swift（内部tableView）
class ToDoTableViewCell: UITableViewCell, UITableViewDataSource, UITableViewDelegate {
// MARK: - Properties
@IBOutlet weak var toDoDateWeekDayLabel: UILabel!
@IBOutlet weak var toDoTableView: UITableView!
var toDos = [ToDo]()
let dateFormatter = DateFormatter()
var toDoDate = Date()
let cellIdentifier = "ToDoGroupTableViewCell"
override var intrinsicContentSize: CGSize {
return self.intrinsicContentSize
}
override func awakeFromNib() {
super.awakeFromNib()
// Initialization code
dateFormatter.dateFormat = "M/d/yy, h:mm a"
sortToDosByWorkDate()
//reloadTableViewData()
}
override func setSelected(_ selected: Bool, animated: Bool) {
super.setSelected(selected, animated: animated)
// Configure the view for the selected state
toDoTableView.delegate = self
toDoTableView.dataSource = self
}
// MARK: - Table view data source
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
//print("Inner Cell Data");
return toDos.count
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cellIdentifier = "ToDoGroupTableViewCell"
let dueDateFormatter = DateFormatter()
let workDateFormatter = DateFormatter()
dueDateFormatter.dateFormat = "M/d/yy, h:mm a"
workDateFormatter.dateFormat = "h:mm a"
guard let cell = tableView.dequeueReusableCell(withIdentifier: cellIdentifier, for: indexPath) as? ToDoGroupTableViewCell else {
fatalError("The dequeued cell is not an instance of ToDoGroupTableViewCell.")
}
// Fetches the appropriate toDo for the data source layout.
let toDo = toDos[indexPath.row]
cell.taskNameLabel.text = toDo.taskName
cell.workDateLabel.text = workDateFormatter.string(from: toDo.workDate)
cell.estTimeLabel.text = toDo.estTime
cell.dueDateLabel.text = dueDateFormatter.string(from: toDo.dueDate)
return cell
}
func tableView(_ tableView: UITableView, canEditRowAt indexPath: IndexPath) -> Bool {
// Return false if you do not want the specified item to be editable.
return true
}
func tableView(_ tableView: UITableView, commit editingStyle: UITableViewCell.EditingStyle, forRowAt indexPath: IndexPath) {
if editingStyle == .delete {
// Delete the row from the data source of the current tableViewCell
let toDoToBeDeleted = toDos[indexPath.row]
tableView.beginUpdates()
toDos.remove(at: indexPath.row)
saveToDos(toDoToBeDeleted: toDoToBeDeleted)
tableView.deleteRows(at: [indexPath], with: .fade)
tableView.endUpdates()
} else if editingStyle == .insert {
// Create a new instance of the appropriate class, insert it into the array, and add a new row to the table view
}
}
// MARK: - Private Methods
private func saveToDos(toDoToBeDeleted: ToDo?) {
// TODO: Refactor the deletion part of this function to be its own delete function
// If there are existing toDos, load them
if var savedToDos = loadToDos() {
// If a there is a specific toDo to be deleted after save
if toDoToBeDeleted != nil {
print("toDoToBeDeleted is not nil")
print(savedToDos)
/*while let toDoIdToDelete = savedToDos.index(of: toDoToBeDeleted!) {
print("Index Exists in savedToDos")
savedToDos.remove(at: toDoIdToDelete)
}*/
savedToDos.removeAll{$0 == toDoToBeDeleted}
let isSuccessfulSave = NSKeyedArchiver.archiveRootObject(savedToDos, toFile: ToDo.ArchiveURL.path)
if isSuccessfulSave {
os_log("A ToDo was deleted and ToDos is successfully saved.", log: OSLog.default, type: .debug)
}
// If there is no specific toDo to be deleted
} else {
let lastToDosItem: Int = toDos.count - 1
savedToDos.append(toDos[lastToDosItem])
let isSuccessfulSave = NSKeyedArchiver.archiveRootObject(savedToDos, toFile: ToDo.ArchiveURL.path)
if isSuccessfulSave {
os_log("A ToDo was added and ToDos is successfully saved.", log: OSLog.default, type: .debug)
}
}
// If this is the initial save and no other toDos exists
} else {
let isSuccessfulSave = NSKeyedArchiver.archiveRootObject(toDos, toFile: ToDo.ArchiveURL.path)
if isSuccessfulSave {
os_log("The initial ToDo is successfully saved.", log: OSLog.default, type: .debug)
}
}
}
private func loadToDos() -> [ToDo]? {
print("loadToDos()")
return NSKeyedUnarchiver.unarchiveObject(withFile: ToDo.ArchiveURL.path) as? [ToDo]
}
private func registerCell() {
toDoTableView.register(ToDoTableViewCell.self, forCellReuseIdentifier: "ToDoTableViewCell")
}
private func sortToDosByWorkDate() {
toDos = toDos.sorted(by: {
$1.workDate > $0.workDate
})
}
}
在tableViewCell内的tableView中删除一行时输出错误：
2019-08-05 00:35:03.610047-0400 Focus-N-Do[1957:40199] *** Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: 'Invalid update: invalid number of rows in section 0. The number of rows contained in an existing section after the update (5) must be equal to the number of rows contained in that section before the update (3), plus or minus the number of rows inserted or deleted from that section (0 inserted, 1 deleted) and plus or minus the number of rows moved into or out of that section (0 moved in, 0 moved out).'
*** First throw call stack:
(
0 CoreFoundation 0x00000001095501bb __exceptionPreprocess + 331
1 libobjc.A.dylib 0x0000000107b66735 objc_exception_throw + 48
2 CoreFoundation 0x000000010954ff42 +[NSException raise:format:arguments:] + 98
3 Foundation 0x0000000107569877 -[NSAssertionHandler handleFailureInMethod:object:file:lineNumber:description:] + 194
4 UIKitCore 0x000000010c0e2e2d -[UITableView _endCellAnimationsWithContext:] + 18990
5 UIKitCore 0x000000010c0fc711 -[UITableView endUpdates] + 75
6 Focus-N-Do 0x00000001071201ac $S10Focus_N_Do02ToB13TableViewCellC05tableE0_6commit8forRowAtySo07UITableE0C_So0leF12EditingStyleV10Foundation9IndexPathVtF + 1036
7 Focus-N-Do 0x000000010712029b $S10Focus_N_Do02ToB13TableViewCellC05tableE0_6commit8forRowAtySo07UITableE0C_So0leF12EditingStyleV10Foundation9IndexPathVtFTo + 123
8 UIKitCore 0x000000010c120d90 __48-[UITableView _animateDeletionOfRowAtIndexPath:]_block_invoke + 71
9 UIKitCore 0x000000010c3b6235 +[UIView(Animation) performWithoutAnimation:] + 90
10 UIKitCore 0x000000010c120bdb -[UITableView _animateDeletionOfRowAtIndexPath:] + 219
11 UIKitCore 0x000000010c129739 __82-[UITableView _contextualActionForDeletingRowAtIndexPath:usingPresentationValues:]_block_invoke + 59
12 UIKitCore 0x000000010c07ef5e -[UIContextualAction executeHandlerWithView:completionHandler:] + 154
13 UIKitCore 0x000000010c084884 -[UISwipeOccurrence _performSwipeAction:inPullview:swipeInfo:] + 725
14 UIKitCore 0x000000010c086128 -[UISwipeOccurrence swipeActionPullView:tappedAction:] + 92
15 UIKitCore 0x000000010c08ad33 -[UISwipeActionPullView _tappedButton:] + 138
16 UIKitCore 0x000000010bedbecb -[UIApplication sendAction:to:from:forEvent:] + 83
17 UIKitCore 0x000000010b9170bd -[UIControl sendAction:to:forEvent:] + 67
18 UIKitCore 0x000000010b9173da -[UIControl _sendActionsForEvents:withEvent:] + 450
19 UIKitCore 0x000000010b91631e -[UIControl touchesEnded:withEvent:] + 583
20 UIKitCore 0x000000010bf170a4 -[UIWindow _sendTouchesForEvent:] + 2729
21 UIKitCore 0x000000010bf187a0 -[UIWindow sendEvent:] + 4080
22 UIKitCore 0x000000010bef6394 -[UIApplication sendEvent:] + 352
23 UIKitCore 0x000000010bfcb5a9 __dispatchPreprocessedEventFromEventQueue + 3054
24 UIKitCore 0x000000010bfce1cb __handleEventQueueInternal + 5948
25 CoreFoundation 0x00000001094b5721 __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE0_PERFORM_FUNCTION__ + 17
26 CoreFoundation 0x00000001094b4f93 __CFRunLoopDoSources0 + 243
27 CoreFoundation 0x00000001094af63f __CFRunLoopRun + 1263
28 CoreFoundation 0x00000001094aee11 CFRunLoopRunSpecific + 625
29 GraphicsServices 0x000000011166b1dd GSEventRunModal + 62
30 UIKitCore 0x000000010beda81d UIApplicationMain + 140
31 Focus-N-Do 0x00000001071230b7 main + 71
32 libdyld.dylib 0x000000010a9e9575 start + 1
)
libc++abi.dylib: terminating with uncaught exception of type NSException
(lldb)
任何帮助将不胜感激。
答案 0 :(得分：0)
问题不在beginUpdates，endUpdates等中，而是在ToDoTableViewCell逻辑中。
错误文本提示您正在删除和/或插入不正确的行数。
请考虑以下示例：
您从数据源（即toDos）中删除了1个对象，并为一个tableView.deleteRows(at: [indexPath], with: .fade)调用了indexPath。
如果是这种情况，一切都会很好。但是错误显示更新之前有3行，现在更新之后有5行。记住，您删除了1行，因此应该有2行。这怎么会发生？..应用程序崩溃。
问题是您正在将对象插入数据源中的某个位置，但没有调用tableView.inserRows(...)。您需要弄清楚这一点。
答案 1 :(得分：0)
在您的项目中，可以使用tableView数据源方法canEditRowAt通过以下方式从tableView中删除项目：
override func tableView(_ tableView: UITableView, canEditRowAt indexPath: IndexPath) -> Bool {
return true
}
override func tableView(_ tableView: UITableView, commit editingStyle: UITableViewCell.EditingStyle, forRowAt indexPath: IndexPath) {
if editingStyle == .delete
{
toDos.remove(at: indexPath.row)
tableView.reloadData()
}
}
请记住要在tableView中重新加载数据，否则更改将不会反映在tableView中。
答案 2 :(得分：0)
在提交编辑方法中删除时，如果要使用开始和结束更新，请不要使用开始或结束更新，然后在editActionsForRowAt中进行perfrom删除
跟随
func tableView(_ tableView: UITableView, commit editingStyle: UITableViewCell.EditingStyle, forRowAt indexPath: IndexPath) {
if editingStyle == .delete {
// Delete the row from the data source of the current tableViewCell
let toDoToBeDeleted = toDos[indexPath.row]
toDos.remove(at: indexPath.row)
tableView.deleteRows(at: [indexPath], with: .fade)
saveToDos(toDoToBeDeleted: toDoToBeDeleted)
} else if editingStyle == .insert {
// Create a new instance of the appropriate class, insert it into the array, and add a new row to the table view
}
}
OR
func tableView(_ tableView: UITableView, editActionsForRowAt indexPath: IndexPath) -> [UITableViewRowAction]? {
let deleteAction = UITableViewRowAction(style: .destructive, title: "Delete") { (rowAction: UITableViewRowAction, indexPath: IndexPath) -> Void in
let toDoToBeDeleted = toDos[indexPath.row]
tableView.beginUpdates()
toDos.remove(at: indexPath.row)
tableView.deleteRows(at: [indexPath], with: .fade)
tableView.endUpdates()
saveToDos(toDoToBeDeleted: toDoToBeDeleted)
}
return [deleteAction]
}
并从commit editStyle方法中删除以下部分
let toDoToBeDeleted = toDos[indexPath.row]
tableView.beginUpdates()
toDos.remove(at: indexPath.row)
saveToDos(toDoToBeDeleted: toDoToBeDeleted)
tableView.deleteRows(at: [indexPath], with: .fade)
tableView.endUpdates()