动态UITextView错位行为

Question

我试图有一个类似于iPhone消息的textview,其中textview最初有一个约束(height <= 100)和scrollEnabled = false

这是项目的链接:https: //github.com/akawther/TextView

文本视图的高度根据内容大小增加,如左图所示,直到达到100的高度,然后scrollEnabled设置为true.它完美无缺,直到我点击右下角的"发送"按钮,其中textView应该变为空并返回到原始高度并且scrollEnabled变为false.中间的图像显示了单击按钮时发生的情况.当我开始输入时,文本视图向下移动,就像您在右侧的最后一张图片中看到的那样.我希望能够单击按钮并消除中间图像上显示的行为,我该如何解决这个问题？

import UIKit

class ViewController: UIViewController, UITextViewDelegate {

@IBOutlet weak var bottomConstraint: NSLayoutConstraint!
@IBOutlet weak var messageTextView: UITextView!
@IBOutlet weak var parent: UIView!
let messageTextViewMaxHeight: CGFloat = 100


override func viewDidLoad() {
    super.viewDidLoad()

    self.messageTextView.delegate = self
}

@IBAction func Reset(sender: AnyObject) {
    messageTextView.text = ""
    messageTextView.frame.size.height = messageTextView.contentSize.height
    messageTextView.scrollEnabled = false
    self.parent.layoutIfNeeded()
}

func textViewDidChange(textView: UITextView) {
    if textView.frame.size.height >= self.messageTextViewMaxHeight {

        textView.scrollEnabled = true

    } else {
        textView.scrollEnabled = false
        textView.frame.size.height = textView.contentSize.height
    }
}

}

您可以通过在github项目中执行以下步骤来复制我的问题:1.保持键入单词并按下输入直到您开始看到滚动2.单击按钮,您将看到textview在蓝色容器中上升.这是我要消除的问题!

Answer 1

尝试以下代码：-

@IBAction func Reset(sender: AnyObject) {
        messageTextView.scrollEnabled = false
        messageTextView.text = ""
        messageTextView.frame.size.height = messageTextView.contentSize.height
        parent.frame.size.height = 20

    self.view.layoutIfNeeded()
}

func textViewDidChange(textView: UITextView) {
    if textView.contentSize.height >= self.messageTextViewMaxHeight {

        textView.scrollEnabled = true

    } else {

        textView.frame.size.height = textView.contentSize.height
        textView.scrollEnabled = false
    }
}