当键盘显示时，Swift ios移动文本字段

Question

我是ios / swift的新手，不知道在文本字段/键盘方面该怎么做。

当我单击文本字段时，键盘会阻止/覆盖它，所以我无法选择它或任何其他文本字段。

那么什么是最好的解决方案呢？ 除了在scrollview中包装所有内容。

我找到了这个片段，但我不确定如何实现它：

func textFieldDidBeginEditing(textField: UITextField) {
            animateViewMoving(true, moveValue: 100)
    }
    func textFieldDidEndEditing(textField: UITextField) {
            animateViewMoving(false, moveValue: 100)
    }

    func animateViewMoving (up:Bool, moveValue :CGFloat){
        var movementDuration:NSTimeInterval = 0.3
        var movement:CGFloat = ( up ? -moveValue : moveValue)
        UIView.beginAnimations( "animateView", context: nil)
        UIView.setAnimationBeginsFromCurrentState(true)
        UIView.setAnimationDuration(movementDuration )
        self.view.frame = CGRectOffset(self.view.frame, 0,  movement)
        UIView.commitAnimations()
    }

或者如果有人从github有一个很好的代码示例/库，请分享:)

提前致谢，

Answer 1

首先，您应该注册两个键盘通知：

NSNotificationCenter.defaultCenter().addObserver(self, selector: "keyboardWillShow:", name: UIKeyboardWillShowNotification, object: nil)
NSNotificationCenter.defaultCenter().addObserver(self, selector: "keyboardWillHide:", name: UIKeyboardWillHideNotification, object: nil)

然后，您应该将文本字段嵌入到UIView （我们将其inputView ）。 接下来，您应该参考视图的顶部（或底部约束）。 以下是具有底部约束的示例：

@IBOutlet weak var inputViewBottomConstraint: NSLayoutConstraint!

接下来，实现两个观察器函数：

func keyboardWillShow(notification : NSNotification) {

    var keyboardSize = notification.userInfo?[UIKeyboardFrameEndUserInfoKey]?.CGRectValue().size

    previousConstant = self.inputViewBottomConstraint.constant
    self.inputViewBottomConstraint.constant = keyboardSize!.height

    UIView.animateWithDuration(0.3, delay: 0, options: UIViewAnimationOptions.CurveLinear, animations: { () -> Void in
        self.layoutIfNeeded()
    })
}

func keyboardWillHide(notification : NSNotification) {

    self.inputViewBottomConstraint.constant = previousConstant
    self.layoutIfNeeded()
}

Answer 2

Swift 3.0 - 如果您的textField在UITableView中

    NotificationCenter.default.addObserver(self, selector:#selector(youViewContorllerName.keyboardWillShow(notification:)), name: NSNotification.Name.UIKeyboardWillShow, object: nil)
    NotificationCenter.default.addObserver(self, selector:#selector(youViewContorllerName.keyboardWillHide(notification:)), name: NSNotification.Name.UIKeyboardWillHide, object: nil)

  func keyboardWillShow(notification : NSNotification) {

        let keyboardSize = (notification.userInfo?[UIKeyboardFrameEndUserInfoKey] as AnyObject).cgRectValue.size

        self.constraintTblBottom.constant = keyboardSize.height
        UIView.animate(withDuration: 0.3, delay: 0, options: UIViewAnimationOptions.curveLinear, animations: { () -> Void in
            self.layoutIfNeeded()
        })
    }

    func keyboardWillHide(notification : NSNotification) {
        self.constraintTblBottom.constant = 0
        self.layoutIfNeeded()
    }