应用程序崩溃如果在滚动 UITableView 时 popViewController

Question

Hello I have UIViewController inside UINavigationController which has a UITableView in it. I'm reseting my data model when user tap back button (which triggers popViewController function of UINavigationController ). If I popViewController , while scrolling UITableView , App crashes on cellForRowAt function. What can cause this problem?

cellForRowAt function:

class MyViewController: UIViewController, TableView... {

var myChecksModel: MyChecksModel!
.
.
.

func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell: MyChecksListTableViewCell = tableView.dequeueReusableCell(withIdentifier: cellId) as? MyChecksListTableViewCell ??
    MyChecksListTableViewCell(style: .default, reuseIdentifier: cellId)
let check = self.myChecksModel.chequeList[indexPath.row]
cell.myChecksData = check
return cell
}

Back Button

@objc func backButtonTapped(_ sender: UIButton) {
DispatchQueue.main.async {
    self.myChecksModel.resetModel()
    self.navigationController?.popViewController(animated: true)
}
}

Reset Model Function

class MyChecksModel: Codable {
var chequeList: [MyClass] = []
func resetModel() {
self.chequeList = []
}

Answer 1

Your app is crashing because of

index out of bound

You should call

self.myChecksModel.resetModel()

In

override func viewDidDisappear(_ animated: Bool) {
      super.viewDidDisappear(animated)

      self.myChecksModel.resetModel()
}