可编辑 UITextView 上的垂直对齐

Question

我想在我的UITextView 上设置垂直对齐。文本视图是可编辑的并且滚动被禁用：

let textView = UITextView(frame: frame)
textView.backgroundColor = .clear
textView.attributedText = myAttributedString
textView.isUserInteractionEnabled = true
textView.isEditable = true
textView.allowsEditingTextAttributes = true
textView.isScrollEnabled = false
textView.textContainerInset = .zero
self.addSubview(textView)

所以，我想做类似的事情：

textView.verticalAlignment = .center

我已经尝试子类化文本视图并添加如下属性：

class MyTextView: UITextView {
    public var verticalAlignment: UIControl.ContentVerticalAlignment = .center {
        didSet {
            let topCorrection: CGFloat
            switch verticalAlignment {
            case .center:
                topCorrection = (bounds.size.height - contentSize.height * zoomScale) / 2.0
            case .bottom:
                topCorrection = (bounds.size.height - contentSize.height * zoomScale)
            case .top, .fill:
                topCorrection = 0
            @unknown default:
                topCorrection = 0
            }
            contentInset.top = max(0, topCorrection)
        }
    }
}

但它似乎不适用于将isScrollEnabled 设置为false。

我在互联网上找到的所有其他解决方案也都不起作用，我有点绝望……你能帮帮我吗？

谢谢

Answer 1

创建自定义文本视图

class CustomTextView: UITextView {
    override var canBecomeFirstResponder: Bool {
        return false
    }

    override var selectedTextRange: UITextRange? {
        get {
            return nil
        } set {

        }
    }

    override func gestureRecognizerShouldBegin(_ gestureRecognizer: UIGestureRecognizer) -> Bool {
        if let tapGestureRecognizer = gestureRecognizer as? UITapGestureRecognizer,
            tapGestureRecognizer.numberOfTapsRequired == 1 {
            return super.gestureRecognizerShouldBegin(gestureRecognizer)
        }

        if let longPressGestureRecognizer = gestureRecognizer as? UILongPressGestureRecognizer,

            longPressGestureRecognizer.minimumPressDuration < 0.325 {
            return super.gestureRecognizerShouldBegin(gestureRecognizer)
        }
        gestureRecognizer.isEnabled = false
        return false
    }
}

将此文本视图用作文本视图的基类

Answer 2

也许您打算使用 UITextField？

let field = UITextField()
field.contentVerticalAlignment = UIControlContentVerticalAlignment.center

或将其设置为 .bottom、.top 等。