func deleteData(id:String){
   
   let fetchRequest = NSFetchRequest<NSManagedObject>(entityName: "User")
   fetchRequest.predicate = NSPredicate(format: "id = '\(id)'")
  
   do
   {
       let test = try context.fetch(fetchRequest)
       
       let objectToDelete = test[0]
       context.delete(objectToDelete)
       
       do{
           try context.save()
       }
       catch(let error)
       {
        print(error.localizedDescription)
       }
       
   }
   catch(let error)
   {
       print(error)
   }

}

这是删除函数

class SecondViewController: UIViewController,UITableViewDelegate,UITableViewDataSource {

var array = [Dictionary<String,String>]()

@IBOutlet weak var tableview: UITableView!

var id = ""

var obj = Dictionary<String,String>()


override func viewDidLoad() {
    super.viewDidLoad()

    self.tableview.delegate = self
    self.tableview.dataSource = self
    
    array = DataHandler.sharedInstance.fetch()
}

func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
    return array.count
}

func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
    
    let obj = array[indexPath.row]
    let cell = tableView.dequeueReusableCell(withIdentifier: "cell") as! TableViewCell
    
    cell.usernameLabel.text = obj["username"]
    cell.emailLabel.text = obj["email"]
    cell.passwordLabel.text = obj["password"]

    cell.updateBtn.addTarget(self, action: #selector(didTapUpdateBtn(sender:)), for: .touchUpInside)
    cell.updateBtn.tag = indexPath.row
    
    return cell
}

 @objc func didTapUpdateBtn(sender:UIButton)
{
    let obj = array[sender.tag]
    let sb = UIStoryboard.init(name: "Main", bundle: nil)
    let vc = sb.instantiateViewController(identifier: "update") as! UpdateViewController
    vc.obj = obj
    self.present(vc, animated: true, completion: nil)
    
}

这是tableview控制器

class TableViewCell: UITableViewCell {

@IBOutlet weak var usernameLabel: UILabel!
@IBOutlet weak var emailLabel: UILabel!
@IBOutlet weak var passwordLabel: UILabel!
@IBOutlet weak var idLabel: UILabel!

@IBOutlet weak var updateBtn: UIButton!
@IBOutlet weak var deleteBtn: UIButton!

override func awakeFromNib() {
    super.awakeFromNib()
    // Initialization code
}

override func setSelected(_ selected: Bool, animated: Bool) {
    super.setSelected(selected, animated: animated)

    // Configure the view for the selected state
}

这是表格视图单元格

我正在用核心数据执行crud操作。我已经执行了3个操作成功，工作很好，但是在删除操作中，我们不需要导航另一个控制器，只需要点击按钮操作就可以执行。我很困惑怎么做，我尝试了很多方法。