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想要能够手动滚动到键盘上方的文本字段

uiscrollview swift3 ios

Sean Zlatnik · 技术社区 · 8 年前

然而,在scrollview上启用滚动并不能解决问题;即使在这种情况下,它仍然不会对平移做出响应。使viewcontroller成为scrollview的代理和重写函数scrollViewDidScroll也是如此。如何让scrollview启用平移,尤其是仅在启用键盘时?

由于发布了一个不太有效的解决方案,我想我会发布我的keyboardWillBeShown和KeyboardWillbehiden代码:

func keyboardWillBeShown(_ sender: Notification)
{
    self.myScrollView.isScrollEnabled = true

    let info: NSDictionary = (sender as NSNotification).userInfo! as NSDictionary
    let value: NSValue = info.value(forKey: UIKeyboardFrameBeginUserInfoKey) as! NSValue
    let keyboardSize: CGSize = value.cgRectValue.size
    let contentInsets: UIEdgeInsets = UIEdgeInsetsMake(0.0, 0.0, keyboardSize.height, 0.0)
    self.myScrollView.contentInset = contentInsets
    self.myScrollView.scrollIndicatorInsets = contentInsets
    self.myScrollView.scrollRectToVisible(self.myScrollView.frame, animated: true)
    var aRect: CGRect = self.view.frame
    aRect.size.height -= keyboardSize.height
    let activeTextFieldRect: CGRect? = activeField?.frame
    let activeTextFieldOrigin: CGPoint? = activeTextFieldRect?.origin
    if activeTextFieldOrigin != nil
    {
        if (!aRect.contains(activeTextFieldOrigin!))
        {
            let scrollpoint : CGPoint = CGPoint(x: 0.0, y: activeField!.frame.origin.y - keyboardSize.height)
            self.myScrollView.setContentOffset(scrollpoint, animated: true)//.scrollRectToVisible((activeField?.frame)!, animated: true)
        }
    }

}

func keyboardWillBeHidden(_ sender: Notification)
{
    myScrollView.isScrollEnabled = false
    let contentInsets: UIEdgeInsets = UIEdgeInsets.zero
    myScrollView.contentInset = contentInsets
    myScrollView.scrollIndicatorInsets = contentInsets
}

2 回复 | 直到 8 年前

Kiester 8 年前

试试这个,

var originalViewCGRect: CGRect?
var originalOffset: CGPoint!

在里面 viewDidLoad 添加键盘观察者

    NotificationCenter.default.addObserver(self
        , selector: #selector(keyboardWillAppear(_:))
        , name: NSNotification.Name.UIKeyboardWillShow
        , object: nil)
    NotificationCenter.default.addObserver(self
        , selector: #selector(keyboardWillDisappear(_:))
        , name: NSNotification.Name.UIKeyboardWillHide
        , object: nil)

最后,添加这些函数

    func keyboardWillAppear(_ notification: Foundation.Notification){
        self.scrollView.scrollRectToVisible(self.scrollView.frame, animated: true)
        let keyboardSize:CGSize = ((notification as NSNotification).userInfo![UIKeyboardFrameBeginUserInfoKey] as! NSValue).cgRectValue.size
        let insets = UIEdgeInsetsMake(0, 0, keyboardSize.height, 0)
        self.scrollView.contentInset = insets
    }


    func keyboardWillDisappear(_ notification: Foundation.Notification){
        let beginFrame = ((notification as NSNotification).userInfo![UIKeyboardFrameBeginUserInfoKey] as! NSValue).cgRectValue
        let endFrame = ((notification as NSNotification).userInfo![UIKeyboardFrameEndUserInfoKey] as! NSValue).cgRectValue
        let delta = (endFrame.origin.y - beginFrame.origin.y)
        self.view.frame = self.originalViewCGRect!
        self.scrollView.setContentOffset(CGPoint(x: 0, y: max(self.scrollView.contentOffset.y - delta, 0)), animated: true)
    }

总之,当显示和/或隐藏键盘时,这将调整滚动视图的内容插入。

希望这有帮助。

固定调整

Sean Zlatnik 8 年前

我想出了如何得到我想要的。设置myScrollView。当键盘显示时,contentSize与屏幕加上键盘一样大,并将其缩小到隐藏键盘时的大小。然后将视图控制器设置为UIScrollViewDelegate,设置myScrollView。delegate=self,并实现scrollViewDidScroll,以便如果某个文本字段正在编辑,并且该文本字段不是空的,则更改哪个文本字段是第一个响应者。一旦你意识到设置的诀窍,那就太容易了。contentSize!