使用swift从文本视图中选择文本后显示副本

你需要这样的东西,它只是状态的问题,如果你的当前状态是一个,你应该在菜单中显示一些东西,你还需要覆盖这些方法中的每一个来改变当前状态

import UIKit

enum MenuState{
    case select
    case copy
    case paste
}

class CustomTextField: UITextField {

    var currentState : MenuState = .select

    override public func canPerformAction(_ action: Selector, withSender sender: Any?) -> Bool
    {
        switch self.currentState {
        case .select:
            if action == #selector(select(_:)) || action == #selector(selectAll(_:)){
                return true
            }
        case .copy:
            if action == #selector(copy(_:)){
                return true
            }
        case .paste:
            if action == #selector(paste(_:)){
                return true
            }
        }
        return false
    }

    override func select(_ sender: Any?) {
        super.select(sender)
        self.currentState = .copy
    }

    override func selectAll(_ sender: Any?) {
        super.selectAll(sender)
        self.currentState = .copy
    }

    override func copy(_ sender: Any?) {
        super.copy(sender)
        self.currentState = .paste
    }

    override func paste(_ sender: Any?) {
        super.paste(sender)
        self.currentState = .select
    }

}