可复制内容的Label

这里有个坑就是如果重载NSObject的copy方法，就会导致弹出菜单永远有一个copy在第一位，如果不重载系统的copy，实现自己的方法就一切OK😄

import UIKit

class UICopyLabel: UILabel {
    
    override init(frame: CGRect) {
        super.init(frame: frame)
        
        attachTapHandler()
    }
    
    required init?(coder aDecoder: NSCoder) {
        super.init(coder: aDecoder)
        
        attachTapHandler()
    }

    override func canBecomeFirstResponder() -> Bool {
        return true
    }

    override func canPerformAction(action: Selector, withSender sender: AnyObject?) -> Bool {
        return action == #selector(UICopyLabel.myCopy(_:))
    }
    
    func myCopy(sender: AnyObject?) {
        let pboard = UIPasteboard.generalPasteboard()
        pboard.string = text
    }
    
    func attachTapHandler() {
        userInteractionEnabled = true
        let long = UILongPressGestureRecognizer(target: self, action: #selector(UICopyLabel.tapHandler(_:)))
        addGestureRecognizer(long)
    }
    
    func tapHandler(recognizer: UIGestureRecognizer) {
        becomeFirstResponder()
        let link = UIMenuItem(title: "copy", action: #selector(UICopyLabel.myCopy(_:)))
        let menuVC = UIMenuController.sharedMenuController()
        menuVC.menuItems = [link]
        menuVC.setTargetRect(frame, inView: superview!)
        menuVC.setMenuVisible(true, animated: true)
    }
    
}