Question

我正在尝试调整tableview的高度。我想在键盘消失时调整它。 tableview高度应该增加。此外，任何有数据的单元格也应该向下移动。它们应该向下移动以反映tableview的新高度。我怎么能这样做？

这是我现在的代码：

@IBOutlet weak var tableView: UITableView!

var items = ["Apple", "Orange", "Banana", "Pear"]

override func viewDidLoad() {
    super.viewDidLoad()

    tableView.rowHeight = UITableViewAutomaticDimension
    tableView.estimatedRowHeight = 140
}

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

 func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
    let cellIdentifier = "Cell"
    guard let cell = tableView.dequeueReusableCell(withIdentifier: cellIdentifier, for: indexPath) as? UITableViewCell else {
        fatalError("The dequeued cell is not an instance of UITableViewCell.")
    }

    var item = items[indexPath.row]
    cell.Label.text = item

    //Some adjustments
    cell.preservesSuperviewLayoutMargins = false
    cell.separatorInset = UIEdgeInsets.zero
    cell.layoutMargins = UIEdgeInsets.zero

    return cell
}

func tableView(_ tableView: UITableView, heightForRowAt indexPath: IndexPath) -> CGFloat {
    return UITableViewAutomaticDimension
}

Answer 1

通过将约束从xib文件拖放到类文件，按如下方式连接tableview的底部约束。（当没有键盘可见时，此底部约束是tableview的底部）

@IBOutlet weak var bottomConstraint: NSLayoutConstraint!

添加如下所示的键盘观察器

    func setKBObservers() {
        NotificationCenter.default.addObserver(self, selector: #selector(self.keyboardWillShow), name: NSNotification.Name.UIKeyboardWillShow, object: nil)
        NotificationCenter.default.addObserver(self, selector: #selector(self.keyboardWillHide), name: NSNotification.Name.UIKeyboardWillHide, object: nil)
    }

根据键盘的可见性修改高度，如下所示

    func keyboardWillShow(notification: NSNotification) {
        if let keyboardSize = (notification.userInfo?[UIKeyboardFrameEndUserInfoKey] as? NSValue)?.cgRectValue {
            bottomConstraint.constant = keyboardSize.height
            view.setNeedsLayout()
            view.layoutIfNeeded()
        }
    }

    func keyboardWillHide(notification: NSNotification) {
        bottomConstraint.constant = 0
        view.setNeedsLayout()
        view.layoutIfNeeded()
    }

Answer 2

    var isKeyboardOpen:Bool = false
    @IBOutlet weak var tblheight: NSLayoutConstraint!

    override func viewWillLayoutSubviews() {
            super.updateViewConstraints()
            let screenHeight = UIScreen.main.bounds.height
            if self.tableView.contentSize.height  > screenHeight{
                if isKeyboardOpen == true{
                     self.tblheight.constant = screenHeight - 320
                }else{
                     self.tblheight.constant = screenHeight - 100
                }

            }
        }
        func tableView(_ tableView: UITableView, willDisplay cell: UITableViewCell, forRowAt indexPath: IndexPath) {
            self.viewWillLayoutSubviews()
        }

// textField Delegate Method..
func textFieldDidBeginEditing(_ textField: UITextField) {
        isKeyboardOpen = true
        viewWillLayoutSubviews()
    }

    func textFieldDidEndEditing(_ textField: UITextField) {
        self.view.endEditing(true)
        isKeyboardOpen = false
        textField.resignFirstResponder()
        viewWillLayoutSubviews()
    }
    func textFieldShouldReturn(_ textField: UITextField) -> Bool {
        isKeyboardOpen = false
        self.view.endEditing(true)
        textField.resignFirstResponder()
        return true
    }

尝试这个..它对我有用。希望它会有所帮助..

动态调整Tableview高度和单元格？

2 个答案: