UITextView 长按复制粘贴怎么设置

你可以通过以下代码实现 UITextView 长按复制粘贴的功能：

// 设置允许复制和粘贴
textView.isSelectable = true
textView.allowsEditingTextAttributes = true
textView.textContainerInset = UIEdgeInsets(top: 10, left: 0, bottom: 10, right: 0)

// 添加长按手势识别器
let longPressGesture = UILongPressGestureRecognizer(target: self, action: #selector(longPress(_:)))
textView.addGestureRecognizer(longPressGesture)

// 长按手势识别器的响应函数
@objc func longPress(_ gestureRecognizer: UIGestureRecognizer) {
    // 获取长按的位置
    let point = gestureRecognizer.location(in: textView)
    
    // 获取长按位置所在的字符索引
    let characterIndex = textView.layoutManager.characterIndex(for: point, in: textView.textContainer, fractionOfDistanceBetweenInsertionPoints: nil)
    
    // 判断长按位置是否在文本范围内
    if characterIndex < textView.textStorage.length {
        // 获取长按位置所在的单词
        let range = textView.tokenizer.rangeEnclosingPosition(TextViewPosition(document: textView.textStorage), with: .word, inDirection: UITextDirection(rawValue: 1))
        let word = textView.text(in: range!)
        
        // 弹出菜单
        let menuController = UIMenuController.shared
        if !menuController.isMenuVisible {
            let copyMenuItem = UIMenuItem(title: "复制", action: #selector(copyText(_:)))
            let pasteMenuItem = UIMenuItem(title: "粘贴", action: #selector(pasteText(_:)))
            menuController.menuItems = [copyMenuItem, pasteMenuItem]
            menuController.setTargetRect(CGRect(x: point.x, y: point.y, width: 0, height: 0), in: textView)
            menuController.setMenuVisible(true, animated: true)
        }
    }
}

// 复制文本
@objc func copyText(_ sender: Any) {
    UIPasteboard.general.string = textView.text(in: textView.selectedTextRange!)
}

// 粘贴文本
@objc func pasteText(_ sender: Any) {
    if let pasteString = UIPasteboard.general.string {
        let selectedRange = textView.selectedRange
        let mutableAttributedString = NSMutableAttributedString(attributedString: textView.attributedText)
        mutableAttributedString.replaceCharacters(in: selectedRange, with: NSAttributedString(string: pasteString))
        textView.attributedText = mutableAttributedString
    }
}

这里使用了 `UITextView` 的 `UITextInputTokenizer` 对象来获取长按位置所在的单词，并通过 `UIMenuController` 弹出菜单来实现复制和粘贴的功能。同时，需要在 `UITextView` 中设置 `isSelectable` 和 `allowsEditingTextAttributes` 属性为 `true`，并添加长按手势识别器来启用长按功能。