UITextView链接可选,无需其他文本可选

Question

我正在尝试获得类似于Facebook使用的设置(如果他们使用的话UITextView).我想要自动检测链接,但我不想在UITextView可选择的任何其他文本.因此,用户可以单击链接但无法选择任何其他文本.

尽管搜索过,我还没有找到一个解决方案,因为链接选择工作它需要整个文本视图可供选择.

Answer 1

如果您的最低部署目标是iOS 11.2或更高版本

您可以通过子类化UITextView和禁止可以选择某些东西的手势来禁用文本选择。

下面的解决方案是：

• 与isEditable兼容
• 与isScrollEnabled兼容
• 与链接兼容

/// Class to allow links but no selection.
/// Basically, it disables unwanted UIGestureRecognizer from UITextView.
/// https://stackoverflow.com/a/49428307/1033581
class UnselectableTappableTextView: UITextView {

    // required to prevent blue background selection from any situation
    override var selectedTextRange: UITextRange? {
        get { return nil }
        set {}
    }

    override func gestureRecognizerShouldBegin(_ gestureRecognizer: UIGestureRecognizer) -> Bool {
        if gestureRecognizer is UIPanGestureRecognizer {
            // required for compatibility with isScrollEnabled
            return super.gestureRecognizerShouldBegin(gestureRecognizer)
        }
        if let tapGestureRecognizer = gestureRecognizer as? UITapGestureRecognizer,
            tapGestureRecognizer.numberOfTapsRequired == 1 {
            // required for compatibility with links
            return super.gestureRecognizerShouldBegin(gestureRecognizer)
        }
        // allowing smallDelayRecognizer for links
        // https://stackoverflow.com/questions/46143868/xcode-9-uitextview-links-no-longer-clickable
        if let longPressGestureRecognizer = gestureRecognizer as? UILongPressGestureRecognizer,
            // comparison value is used to distinguish between 0.12 (smallDelayRecognizer) and 0.5 (textSelectionForce and textLoupe)
            longPressGestureRecognizer.minimumPressDuration < 0.325 {
            return super.gestureRecognizerShouldBegin(gestureRecognizer)
        }
        // preventing selection from loupe/magnifier (_UITextSelectionForceGesture), multi tap, tap and a half, etc.
        gestureRecognizer.isEnabled = false
        return false
    }
}

如果您的最低部署目标是iOS 11.1或更早版本

本机UITextView链接手势识别器在iOS 11.0-11.1上已损坏，并且需要长时间按住而不是轻按以延迟一下：Xcode 9 UITextView链接不再可单击

您可以使用自己的手势识别器正确支持链接，并且可以通过子类化UITextView和禁止选择或轻敲某些手势来禁用文本选择。

以下解决方案将不允许选择，并且是：

• 与isScrollEnabled兼容
• 与链接兼容
• iOS 11.0和iOS 11.1的变通办法限制，但在点击文本附件时失去UI效果

/// Class to support links and to disallow selection.
/// It disables most UIGestureRecognizer from UITextView and adds a UITapGestureRecognizer.
/// https://stackoverflow.com/a/49428307/1033581
class UnselectableTappableTextView: UITextView {

    required init?(coder aDecoder: NSCoder) {
        super.init(coder: aDecoder)

        // Native UITextView links gesture recognizers are broken on iOS 11.0-11.1:
        // https://stackoverflow.com/questions/46143868/xcode-9-uitextview-links-no-longer-clickable
        // So we add our own UITapGestureRecognizer.
        linkGestureRecognizer = UITapGestureRecognizer(target: self, action: #selector(textTapped))
        linkGestureRecognizer.numberOfTapsRequired = 1
        addGestureRecognizer(linkGestureRecognizer)
        linkGestureRecognizer.isEnabled = true
    }

    var linkGestureRecognizer: UITapGestureRecognizer!

    // required to prevent blue background selection from any situation
    override var selectedTextRange: UITextRange? {
        get { return nil }
        set {}
    }

    override func addGestureRecognizer(_ gestureRecognizer: UIGestureRecognizer) {
        // Prevents drag and drop gestures,
        // but also prevents a crash with links on iOS 11.0 and 11.1.
        // https://stackoverflow.com/a/49535011/1033581
        gestureRecognizer.isEnabled = false
        super.addGestureRecognizer(gestureRecognizer)
    }

    override func gestureRecognizerShouldBegin(_ gestureRecognizer: UIGestureRecognizer) -> Bool {
        if gestureRecognizer == linkGestureRecognizer {
            // Supporting links correctly.
            return super.gestureRecognizerShouldBegin(gestureRecognizer)
        }
        if gestureRecognizer is UIPanGestureRecognizer {
            // Compatibility support with isScrollEnabled.
            return super.gestureRecognizerShouldBegin(gestureRecognizer)
        }
        // Preventing selection gestures and disabling broken links support.
        gestureRecognizer.isEnabled = false
        return false
    }

    @objc func textTapped(recognizer: UITapGestureRecognizer) {
        guard recognizer == linkGestureRecognizer else {
            return
        }
        var location = recognizer.location(in: self)
        location.x -= textContainerInset.left
        location.y -= textContainerInset.top
        let characterIndex = layoutManager.characterIndex(for: location, in: textContainer, fractionOfDistanceBetweenInsertionPoints: nil)
        let characterRange = NSRange(location: characterIndex, length: 1)

        if let attachment = attributedText?.attribute(.attachment, at: characterIndex, effectiveRange: nil) as? NSTextAttachment {
            if #available(iOS 10.0, *) {
                _ = delegate?.textView?(self, shouldInteractWith: attachment, in: characterRange, interaction: .invokeDefaultAction)
            } else {
                _ = delegate?.textView?(self, shouldInteractWith: attachment, in: characterRange)
            }
        }
        if let url = attributedText?.attribute(.link, at: characterIndex, effectiveRange: nil) as? URL {
            if #available(iOS 10.0, *) {
                _ = delegate?.textView?(self, shouldInteractWith: url, in: characterRange, interaction: .invokeDefaultAction)
            } else {
                _ = delegate?.textView?(self, shouldInteractWith: url, in: characterRange)
            }
        }
    }
}

Answer 2

您可以将UITextView覆盖方法的子类化selectedTextRange，将其设置为nil。并且链接仍然可以单击，但是您将无法选择文本的其余部分（即使是链接，也可以单击它）。

class CustomTextView: UITextView {
override public var selectedTextRange: UITextRange? {
    get {
        return nil
    }
    set { }
}

Answer 3

这个答案适用于 iOS 10.3.x 及更低版本，其中您的 UIView 未嵌入子视图中。如需更可靠、更现代的答案，请参阅下面 C\xc5\x93ur\ 的答案。

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您需要防止他们UITextView成为第一响应者。

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1. 子类UITextView化为您自己的自定义类 ( MyTextView)。

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2. 覆盖canBecomeFirstResponder()。这是 Swift 中的示例：

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斯威夫特3：

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class MyTextView: UITextView {\n    override func becomeFirstResponder() -> Bool {\n        return false\n    }\n}\n

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斯威夫特2：

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class MyTextView: UITextView {\n    override func canBecomeFirstResponder() -> Bool {\n        return false\n    }\n}\n

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检测到的任何链接仍将启用。我用电话号码对此进行了测试。

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