[英]tableview select row after reload data infinite loop
我有一個tableView在每個單元格中都有一個textField列表,並且使用UITextFieldDelegate。 用戶可以寫自己想要的內容並添加行。
問題在於必須重新加載tableview才能將結果顯示給用戶,但它破壞了beginFirstResponder()的功能。
我在self.tableView.reloadData()
之后嘗試了這種解決方案:
1
let cell = self.tableView.dequeueReusableCell(withIdentifier: Cell.identifier, for: IndexPath(item: 0, section: 0)) as! Cell
textFieldDidBeginEditing(cell.textFiedl)
2
let cell = tableView(self.tableView, cellForRowAt: indexPath) as! CellItemOptions
cell.nameOptionsItem.becomeFirstResponder()
3
let cell = self.tableView.cellForRow(at: indexPath) as! CellItemOptions
cell.nameOptionsItem.becomeFirstResponder()
但這是行不通的。
謝謝您的幫助 !
編輯:我的代碼
import UIKit
class OptionsItemViewController: UIViewController, UITableViewDataSource, UITableViewDelegate, UITextFieldDelegate {
let context = (UIApplication.shared.delegate as! AppDelegate).persistentContainer.viewContext
var textFiedlDelegate: UITextField? = nil
var categorySelected: Category?
var options: [String] = []
var nameOptions: [String] = []
var cellSelected: Int = 0
var viewHeight: CGFloat = 0
var selectedRow: IndexPath? = nil
var tableviewNeedToReload: Bool = false
@IBOutlet weak var tableView: UITableView!
@IBOutlet weak var keyboardAlwaysShow: UITextField!
@IBOutlet weak var newFeatureButton: UIBarButtonItem!
private let db = DataBase()
override func viewDidLoad() {
super.viewDidLoad()
self.tableView.dataSource = self
self.textFiedlDelegate?.delegate = self
self.title = categorySelected!.name
NotificationCenter.default.addObserver(self, selector: #selector(keyboardWillShow), name: NSNotification.Name.UIKeyboardWillShow, object: nil)
NotificationCenter.default.addObserver(self, selector: #selector(keyboardWillHide), name: NSNotification.Name.UIKeyboardWillHide, object: nil)
}
override func viewWillAppear(_ animated: Bool) {
super.viewWillAppear(animated)
db.getItemOptions(predicateFormat: "id == \(self.categorySelected!.id)", completion: { results in
self.categorySelected = results.first!
self.options = self.categorySelected!.options as! [String]
DispatchQueue.main.async {
self.tableView.reloadData()
}
})
}
override func viewDidAppear(_ animated: Bool) {
super.viewDidAppear(false)
self.viewHeight = self.view.frame.size.height
}
override func viewDidDisappear(_ animated: Bool) {
super.viewDidDisappear(false)
var index = 0
while index < self.options.count {
if self.options[index] != "" {
index += 1
} else {
self.options.remove(at: index)
}
db.setCategoryOptions(category: self.categorySelected!, options: self.options, index: cellSelected)
}
}
override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
self.view.endEditing(true)
}
@IBAction func newFeature(_ sender: Any) {
if self.options.last != "" {
let indexPath: IndexPath = IndexPath(row: self.options.count, section: 0)
self.options.append("")
self.tableView.reloadData()
let cell = tableView(self.tableView, cellForRowAt: indexPath) as! CellItemOptions
cell.nameOptionsItem.becomeFirstResponder()
}
}
// MARK: - TableView Functions
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return options.count
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let option = options[indexPath.row]
let cell = tableView.dequeueReusableCell(withIdentifier: CellItemOptions.identifier, for: indexPath) as! CellItemOptions
cell.nameOptionsItem.delegate = self
cell.configureCell(with: option)
return cell
}
func textFieldDidBeginEditing(_ textField: UITextField) {
self.cellSelected = options.index(of: textField.text!)!
let indexPath: IndexPath = IndexPath(row: self.cellSelected, section: 0)
self.tableView.reloadData()
let cell = self.tableView.cellForRow(at: indexPath) as! CellItemOptions
cell.nameOptionsItem.becomeFirstResponder()
}
func textFieldDidEndEditing(_ textField: UITextField) {
if textField.text! == "" {
if self.options[cellSelected] != "" {
db.setRemoveDetailsItem(category: self.categorySelected!, index: cellSelected)
}
self.options.remove(at: cellSelected)
} else {
self.options[cellSelected] = "\(textField.text!)"
db.setAddDetailsItem(category: self.categorySelected!, index: cellSelected)
}
db.setCategoryOptions(category: self.categorySelected!, options: self.options, index: cellSelected)
}
// MARK: - Keyboard
func keyboardWillShow(_ notification: NSNotification) {
if let keyboardSize = (notification.userInfo?[UIKeyboardFrameBeginUserInfoKey] as? NSValue)?.cgRectValue {
if self.view.frame.size.height == self.viewHeight {
self.view.frame.size.height -= keyboardSize.height
}
}
}
func keyboardWillHide(_ notification: NSNotification) {
if let keyboardSize = (notification.userInfo?[UIKeyboardFrameBeginUserInfoKey] as? NSValue)?.cgRectValue {
if self.view.frame.origin.y != self.viewHeight {
self.view.frame.size.height += keyboardSize.height
}
}
}
}
class CellItemOptions: UITableViewCell {
static let identifier = "OptionsItemCell"
@IBOutlet weak var nameOptionsItem: UITextField!
private let tableView = OptionsItemViewController()
func configureCell(with cell: String) {
nameOptionsItem.text = cell
}
}
使用此代碼的問題是內存使用量增加,而CPU的使用率大約為100%! 我認為我已經創建了一個無限的指令,但是我沒有找到...
謝謝 !
因此,首先,#3絕對是您想要的。 #1和#2都只能由表視圖調用以實際設置單元格。 您不應該直接給他們打電話。 #3向tableview詢問已經存在的單元格(如果該索引路徑可見),這就是您想要的。
#3的代碼本身看起來還不錯,所以問題可能出在其他地方,您可以發布重新加載時調用的其余代碼嗎?
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