如何在UITextView中向UIMenuController添加自定义UIMenuItem？

let customMenuItem = UIMenuItem(title: "自定义菜单项", action: #selector(customMenuItemAction))

@objc func customMenuItemAction() {
    // 处理自定义菜单项的触发事件
}

func textViewShouldBeginEditing(_ textView: UITextView) -> Bool {
    let menuController = UIMenuController.shared
    menuController.menuItems = [customMenuItem]
    return true
}

func textView(_ textView: UITextView, shouldChangeTextIn range: NSRange, replacementText text: String) -> Bool {
    if text == "自定义触发字符" {
        let menuController = UIMenuController.shared
        menuController.setTargetRect(textView.frame, in: textView.superview!)
        menuController.setMenuVisible(true, animated: true)
    }
    return true
}