如何使用swift在UITableView中有UITextFields时管理键盘？

Posted 2021-04-10

我试图找到一种方法来避免键盘不阻止动态表视图中的选定文本字段。

我知道这是一个常见的问题，并且有很多答案。但是，我发现的答案是Obj-C或不涉及动态UITableView。

我的表视图有自己的UITableViewCell，所以UITextFields连接到它。

另外，我想在创建UITextField条目时刷新单元格。我可以将该信息（我猜单元格的IndexPath.row？）传递给UIViewController并让它监听更改并应用重载单元格方法？

这是我的相关代码：

class favCell: UITableViewCell, UITextFieldDelegate {

    @IBOutlet weak var deciPadField: UITextField!

    @objc func doneClicked(){
        updateTotalWorth()
        deciPadField.resignFirstResponder()
        deciPadField.endEditing(true)
    }

    func textFieldDidBeginEditing(_ textField: UITextField) {
        deciPadField.becomeFirstResponder()
    }

    func textField(_ textField: UITextField, shouldChangeCharactersIn range: NSRange, replacementString string: String) -> Bool {
        let currentString: NSString = (textField.text ?? "") as NSString
        let newString = currentString.replacingCharacters(in: range, with: string)
        return  newString.count <= 10
    }

    func textFieldShouldReturn(_ textField: UITextField) -> Bool {
        updateTotalWorth()
        deciPadField.resignFirstResponder()
        return true
    }

    private func textViewDidEndEditing(_ textView: UITextView) {
        updateTotalWorth()
        deciPadField.endEditing(true)
    }
}

更新：

如果我可以从UITableViewCell访问我的ViewControllers视图，下面的代码可以解决这个问题：

func animateTextField(textField: UITextField, up: Bool) {
    let movementDistance:CGFloat = -130
    let movementDuration: Double = 0.3
    var movement:CGFloat = 0

    if up {
        movement = movementDistance
    } else {
        movement = -movementDistance
    }
    UIView.beginAnimations("animateTextField", context: nil)
    UIView.setAnimationBeginsFromCurrentState(true)
    UIView.setAnimationDuration(movementDuration)

    // Below line giving error, could not find the view. My ListVC.view should be referred to.
    self.view.frame = self.view.frame.offsetBy(dx: 0, dy: movement)

    UIView.commitAnimations()
}


func textFieldDidBeginEditing(textField: UITextField) {
    self.animateTextField(textField: textField, up:true)
}

func textFieldDidEndEditing(textField: UITextField) {
    self.animateTextField(textField: textField, up:false)
}

谢谢！

答案

好吧，我终于想出了如何解决这个问题。我实现了这个答案：https://stackoverflow.com/a/41040630/4441676

这是解决的代码：

在ViewController里面，ViewDidLoad添加了两个观察者，如下所示：

// Notification Observers
    NotificationCenter.default.addObserver(self, selector: #selector(ListVC.keyboardWillShow(notification:)), name: Notification.Name.UIKeyboardDidShow, object: nil)
    NotificationCenter.default.addObserver(self, selector: #selector(ListVC.keyboardWillHide(notification:)), name: Notification.Name.UIKeyboardDidHide, object: nil)

并添加了相关的两个功能：

@objc func keyboardWillShow(notification: Notification) {
    if let keyboardHeight = (notification.userInfo?[UIKeyboardFrameEndUserInfoKey] as? NSValue)?.cgRectValue.height {
        tableView.contentInset = UIEdgeInsetsMake(0, 0, keyboardHeight, 0)
    }
}

@objc func keyboardWillHide(notification: Notification) {
    UIView.animate(withDuration: 0.2, animations: {
        // For some reason adding inset in keyboardWillShow is animated by itself but removing is not, that's why we have to use animateWithDuration here
        self.tableView.contentInset = UIEdgeInsetsMake(0, 0, 0, 0)
    })
}

在连接UITextFields的UITableViewCell中，只需实现UITextField Delegate并在键盘显示/隐藏时添加相关的Notification.posts：

deciPadField.delegate = self

func textFieldDidBeginEditing(_ textField: UITextField) {
    NotificationCenter.default.post(name: Notification.Name.UIKeyboardDidShow, object: self)
}

func textFieldDidEndEditing(_ textField: UITextField) {
    NotificationCenter.default.post(name: Notification.Name.UIKeyboardDidHide, object: self)
}

我有inputAccessoryView，因此通过以下方式解除键盘处理：

// Decipad config for adding Done button above itself
let toolBar = UIToolbar()
toolBar.sizeToFit()
let flexiableSpace = UIBarButtonItem(barButtonSystemItem: UIBarButtonSystemItem.flexibleSpace, target: nil, action: nil)
let doneButton = UIBarButtonItem(barButtonSystemItem: UIBarButtonSystemItem.done, target: self, action: #selector(self.doneClicked))
toolBar.setItems([flexiableSpace, doneButton], animated: false)

@objc func doneClicked(){
    updateTotalWorth()
    deciPadField.resignFirstResponder()
    deciPadField.endEditing(true)
}

希望这对其他人有帮助。