iOS Swift -动态增加 UITextView 高度和父 UIView

标签: UITextView ios Swift
发布时间: 2016/4/30 20:59:07
注意事项: 本文中文内容可能为机器翻译,如要查看英文原文请点击上面连接.

我几乎能整个移动 UITextView 在键盘上方,增加减小其高度基于文本的数量,然后再将其返回到其原始位置。然而,我有问题父 UIView,UITextView 长相厮守。

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如果我取消注释要为其更新的大小更新父 UIView 的 updateParentView() 方法的最后一行,没有什么改变的大小,包括 UITextView。

class ViewController: UIViewController, UITextViewDelegate {

    var kPreferredTextViewToKeyboardOffset: CGFloat = 0.0
    var keyboardFrame: CGRect = CGRect.nullRect
    var keyboardIsShowing: Bool = false

    @IBOutlet weak var commentView: UIView!
    @IBOutlet weak var textView: UITextView!
    @IBOutlet weak var sendButton: UIButton!

    override func viewDidLoad() {
        super.viewDidLoad()

        // Do any additional setup after loading the view.

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

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

        // Make it look like UITextField
        self.textView.contentInset = UIEdgeInsetsMake(0.0, 0.0, 0.0, 0.0)
        self.textView.sizeToFit()
        let lightestGrayColor: UIColor = UIColor( red: 224.0/255.0, green: 224.0/255.0, blue:224.0/255.0, alpha: 1.0 )
        self.textView.layer.borderColor = lightestGrayColor.CGColor
        self.textView.layer.borderWidth = 0.6
        self.textView.layer.cornerRadius = 6.0
        self.textView.clipsToBounds = true
        self.textView.layer.masksToBounds = true
    }

    override func viewWillDisappear(animated: Bool) {
        super.viewWillDisappear(animated)
        NSNotificationCenter.defaultCenter().removeObserver(self)
    }

    func keyboardWillShow(notification: NSNotification)
    {
        self.keyboardIsShowing = true

        if let info = notification.userInfo {
            self.keyboardFrame = (info[UIKeyboardFrameEndUserInfoKey] as NSValue).CGRectValue()
            self.arrangeViewOffsetFromKeyboard()
        }

    }

    func keyboardWillHide(notification: NSNotification)
    {
        self.keyboardIsShowing = false

        self.returnViewToInitialFrame()
    }

    func arrangeViewOffsetFromKeyboard()
    {
        var theApp: UIApplication = UIApplication.sharedApplication()
        var windowView: UIView? = theApp.delegate!.window!

        var textFieldLowerPoint: CGPoint = CGPointMake(self.commentView!.frame.origin.x, self.commentView!.frame.origin.y + self.commentView!.frame.size.height)

        var convertedTextViewLowerPoint: CGPoint = self.view.convertPoint(textFieldLowerPoint, toView: windowView)

        var targetTextViewLowerPoint: CGPoint = CGPointMake(self.commentView!.frame.origin.x, self.keyboardFrame.origin.y - kPreferredTextViewToKeyboardOffset)

        var targetPointOffset: CGFloat = targetTextViewLowerPoint.y - convertedTextViewLowerPoint.y
        var adjustedViewFrameCenter: CGPoint = CGPointMake(self.view.center.x, self.view.center.y + targetPointOffset)

        UIView.animateWithDuration(0.2, animations:  {
            self.view.center = adjustedViewFrameCenter
        })
    }

    func returnViewToInitialFrame()
    {
        var initialViewRect: CGRect = CGRectMake(0.0, 0.0, self.view.frame.size.width, self.view.frame.size.height)

        if (!CGRectEqualToRect(initialViewRect, self.view.frame))
        {
            UIView.animateWithDuration(0.2, animations: {
                self.view.frame = initialViewRect
            });
        }
    }

    func textViewDidBeginEditing(textView: UITextView) {
        //
        print("text view did begin editing\n")
        //
        if(self.keyboardIsShowing)
        {
            self.arrangeViewOffsetFromKeyboard()
        }
    }

    func textViewDidChange(textView: UITextView) {
        print("text view did change\n")
        let textViewFixedWidth: CGFloat = self.textView.frame.size.width
        let newSize: CGSize = self.textView.sizeThatFits(CGSizeMake(textViewFixedWidth, CGFloat(MAXFLOAT)))
        var newFrame: CGRect = self.textView.frame
        //
        var textViewYPosition = self.textView.frame.origin.y
        var heightDifference = self.textView.frame.height - newSize.height
        //
        if (abs(heightDifference) > 5) {
            newFrame.size = CGSizeMake(fmax(newSize.width, textViewFixedWidth), newSize.height)
            newFrame.offset(dx: 0.0, dy: heightDifference)
            //
            updateParentView(heightDifference: heightDifference)
        }
        self.textView.frame = newFrame
    }

    func updateParentView(#heightDifference: CGFloat) {
        //
        var newContainerViewFrame: CGRect = self.commentView.frame
        //
        var containerViewHeight = self.commentView.frame.size.height
        print("container view height: \(containerViewHeight)\n")
        //
        var newContainerViewHeight = containerViewHeight - heightDifference
        print("new container view height: \(newContainerViewHeight)\n")
        //
        var containerViewHeightDifference = containerViewHeight - newContainerViewHeight
        print("container view height difference: \(containerViewHeightDifference)\n")
        //
        newContainerViewFrame.size = CGSizeMake(self.commentView.frame.size.width, newContainerViewHeight)
        //
        newContainerViewFrame.offset(dx: 0.0, dy: containerViewHeightDifference)
        //
        // self.commentView.frame = newContainerViewFrame
    }

    func textViewDidEndEditing(textView: UITextView) {
        //
        print("text view did end editing\n")
        //
        textView.resignFirstResponder()
    }

}

解决方法 1:

这是什么为我工作。对我而言,我有查看以下表格视图的文本。因此,随着文本视图的高度,父视图实际上不需要做出什么改变-视图上方的文本视图是什么需要调整大小 (对我来说它是表视图)。所以,这里是我实现的 updateParentView 函数。

func updateParentView(heightDifference: CGFloat) {
    //
    var newContainerViewFrame: CGRect = self.commentTableView.frame
    //
    let containerViewHeight = self.commentTableView.frame.size.height
    print("container view height: \(containerViewHeight)\n")
    //
    let newContainerViewHeight = containerViewHeight + heightDifference
    print("new container view height: \(newContainerViewHeight)\n")
    //
    let containerViewHeightDifference = containerViewHeight - newContainerViewHeight
    print("container view height difference: \(containerViewHeightDifference)\n")
    //
    newContainerViewFrame.size = CGSizeMake(self.commentTableView.frame.size.width, newContainerViewHeight)
    //
    newContainerViewFrame.origin.y - containerViewHeightDifference
    //
    self.commentTableView.frame = newContainerViewFrame
}

现在,随着文本视图增加高度,表视图"向上滑"每 newContainerViewFrame.origin.y - containerViewHeightDifference 。看看下面的截图。

Example Screenshot

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