启用键盘时向上移动按钮

Question

这是我编写的用于在启用键盘时向上移动按钮的代码：

@IBOutlet var lastNameText: HoshiTextField! 
@IBOutlet var firstNameText: HoshiTextField!

override func viewDidLoad() {      
        var fab = MDCFloatingButton()
        fab.translatesAutoresizingMaskIntoConstraints = false
        fab.trailingAnchor.constraint(equalTo: view.trailingAnchor, constant:-30.0).isActive = true
        fab.bottomAnchor.constraint(equalTo: view.bottomAnchor, constant:-240.0).isActive = true
        NotificationCenter.default.addObserver(self, selector: #selector(keyboardWillShow), name:.UIKeyboardWillShow, object: nil )
        NotificationCenter.default.addObserver(self, selector: #selector(keyboardWillHide), name:.UIKeyboardWillHide, object: nil)

        @objc func keyboardWillShow(notificaion: NSNotification) {
            if let keyboardSize = (notificaion.userInfo?[UIKeyboardFrameEndUserInfoKey] as? NSValue)?.cgRectValue{
                //fab = UIButton(frame: CGRect(10+20, self.view.frame.size.height - keyboardSize.height - 40,80,30))     
                fab.frame = CGRect(x: 320, y: 350, width: 60, height: 60)    
        }       
 }

@objc func keyboardWillHide(notification: NSNotification ) {
    if let keyboardSize = (notification.userInfo?[UIKeyboardFrameEndUserInfoKey] as? NSValue)?.cgRectValue{
        fab.frame = CGRect(x: 320, y: 350, width: 65, height: 65)
    }
}

请提供意见。

Answer 1

您需要为按钮添加底部约束，并以编程方式更改此约束的常量。首先，您需要将 Observers 添加到 viewDidLoad() 方法。

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)

并添加选择器方法：

func keyboardWillShow(notification:NSNotification){
    var userInfo = notification.userInfo!
    var keyboardFrame:CGRect = (userInfo[UIKeyboardFrameBeginUserInfoKey] as! NSValue).cgRectValue
    keyboardFrame = self.view.convert(keyboardFrame, from: nil)

    bottom.constant = keyboardFrame.size.height
}

func keyboardWillHide(notification:NSNotification){
    bottom.constant = 0
}

Answer 2

首先在您的 class 中添加文本字段委托方法，然后简单地放置此代码并根据您的需要进行更改：-

func textFieldDidBeginEditing(_ textField: UITextField) {
    switch textField {
    case txtFldSponsorID:
        moveTextfield(textfield: txtFldSponsorID, moveDistance: 0, up: true)
    case txtFldFullName:
        moveTextfield(textfield: txtFldFullName, moveDistance: -10, up: true)
    case txtFldEmail:
        moveTextfield(textfield: txtFldEmail, moveDistance: -10, up: true)
    case txtFldMobile:
        moveTextfield(textfield: txtFldMobile, moveDistance: -10, up: true)
    case txtFldAddress:
        moveTextfield(textfield: txtFldAddress, moveDistance: -80, up: true)
    case txtFldCity:
        moveTextfield(textfield: txtFldCity, moveDistance: -80, up: true)
    default:
        break
    }
}

func textFieldDidEndEditing(_ textField: UITextField) {
    switch textField {
    case txtFldSponsorID:
        moveTextfield(textfield: txtFldSponsorID, moveDistance: 0, up: true)
    case txtFldFullName:
        moveTextfield(textfield: txtFldFullName, moveDistance: 10, up: true)
    case txtFldEmail:
        moveTextfield(textfield: txtFldEmail, moveDistance: 10, up: true)
    case txtFldMobile:
        moveTextfield(textfield: txtFldMobile, moveDistance: 10, up: true)
    case txtFldAddress:
        moveTextfield(textfield: txtFldAddress, moveDistance: 80, up: true)
    case txtFldCity:
        moveTextfield(textfield: txtFldCity, moveDistance: 80, up: true)
    default:
        break
    }
}

Answer 3

更新为Swift 4.+

viewDidLoad

//  Moving next button when keyboard appears
NotificationCenter.default.addObserver(self, selector: #selector(self.keyboardWillShow(notification:)), name:UIResponder.keyboardWillShowNotification, object: nil)
NotificationCenter.default.addObserver(self, selector: #selector(self.keyboardWillHide(notification:)), name:UIResponder.keyboardWillHideNotification, object: nil)

显示键盘时：

@objc func keyboardWillShow(notification:NSNotification){
    let userInfo = notification.userInfo!
    var keyboardFrame:CGRect = (userInfo[UIResponder.keyboardFrameEndUserInfoKey] as! NSValue).cgRectValue
    keyboardFrame = self.view.convert(keyboardFrame, from: nil)
    self.buttonNextBottomConstraint.constant = keyboardFrame.size.height
}

隐藏键盘时：

@objc func keyboardWillHide(notification:NSNotification){
    self.buttonNextBottomConstraint.constant = 0
}

启用键盘时向上移动按钮

Moving button up when keyboard is enabled

uibutton

nsnotifications

ios

swift

material-design