UITextView link 可选，其余文本不可选

Question

我正在尝试获得类似于 Facebook 使用的设置（如果他们使用 UITextView）。我希望 links 被自动检测到，但是我不希望 UITextView selectable 中的任何其他文本。因此，用户可以单击 link 但无法 select 任何其他文本。

尽管四处搜索，但我还没有找到 link selection 要工作的解决方案，它需要整个文本视图 select 可用。

Answer 1

此答案适用于 iOS10.3.x 及以下您的 UIView 未嵌入子视图的地方。如需更强大、更现代的答案，请参阅 .

您需要防止 UITextView 成为第一响应者。

1。 Subclass UITextView 到您自己的自定义 class (MyTextView).

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

Swift 3:

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

Swift 2:

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

检测到的任何链接仍将启用。我用 phone 数字测试了这个。

Answer 2

您需要继承 UITextView 并覆盖 gestureRecognizerShouldBegin (_:) 方法，如下所示：

override func gestureRecognizerShouldBegin(_ gestureRecognizer: UIGestureRecognizer) -> Bool {
    if isEditable == false {
        if let gesture =  gestureRecognizer as? UILongPressGestureRecognizer, gesture.minimumPressDuration == 0.5 {
            return false
        }
    }
    return true
}

这将防止 textview 被 selected 但 link 将按预期工作

已编辑：事实证明，当双击并按住时，您仍然可以 select 文本。正如我发现它发生在两次点击之后（不是带有属性 "minimalNumberOfTaps" 的 UITapGesture，而是一个接一个地不同的点击），所以解决方案是在第一步之后跟踪时间（大约 0.7 秒）完整代码：

var lastTapTime: TimeInterval = 0
    override func gestureRecognizerShouldBegin(_ gestureRecognizer: UIGestureRecognizer) -> Bool {
        if isEditable == false {
            if let gesture =  gestureRecognizer as? UILongPressGestureRecognizer, gesture.minimumPressDuration == 0.5 {
        return false
            }
        }
        if Date().timeIntervalSince1970 >= lastTapTime + 0.7 {
            lastTapTime = Date().timeIntervalSince1970
            return true
        } else {
            return false
        }
    }

这不是最优雅的解决方案，但它似乎有效 ‍♂️

Answer 3

我选择的答案不适用，我不喜欢比较内部 UIGestureRecognizers 中未确认的值。

我的解决方案是覆盖 point(inside:with:) 并允许在用户未点击链接文本时点击：

Answer 4

这对我有用；

class LinkDetectingTextView: UITextView {
    override func gestureRecognizerShouldBegin(_ gestureRecognizer: UIGestureRecognizer) -> Bool {
        if isEditable == false {
            if let _ = gestureRecognizer as? UITapGestureRecognizer {
                return false
            }

            if let longPressRecognizer = gestureRecognizer as? UILongPressGestureRecognizer,
                longPressRecognizer.minimumPressDuration == 0.5 { // prevent to select text but allow certain functionality in application

                return false
            }
        }

        return true
    }
}

此外，在应用程序中将 longPressGestureRecognizer 的 minimumPressDuration 设置为不同于 0.5 的另一个值。

Answer 5

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 并禁止可以 select 某些东西的手势来禁用文本 selection。

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.
/// 
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
        // 
        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

原生 UITextView 链接手势识别器在 iOS 11.0-11.1 上损坏，需要 小延迟长按 而不是点击: Xcode 9 UITextView links no longer clickable

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 禁用文本 selection 并禁止可以 select 某些东西或点击某些东西的手势。

下面的解决方案将不允许 selection 并且是：

与 isScrollEnabled 兼容
与链接兼容
iOS 11.0 和 iOS 11.1 的解决方法限制，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.
/// 
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:
        // 
        // 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.
        // 
        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 6

您可以子类化 UITextView 覆盖 selectedTextRange 的方法，将其设置为 nil。 link 仍然可以点击，但您将无法 select 其余文本（即使是 link，但您可以点击它）。

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

UITextView link 可选，其余文本不可选

UITextView link selectable without rest of text being selectable

hyperlink

selection

uitextview

ios

如果您的最低部署目标是 iOS 11.2 或更高版本

如果您的最低部署目标是 iOS 11.1 或更早版本