swift 3--- UIMenuController 简单使用

今天用swift 3.0 写UIMenuController 遇到一个坑，分享给大家

（1）懒加载 UIMenuController

    private lazy var menuController:UIMenuController = {
    let menu = UIMenuController.shared
    let deleteItem = UIMenuItem(title: "Delete", action: #selector(self.deleteLine))
    let editItems = UIMenuItem(title: "Edit", action: #selector(self.editRow))
    menu.menuItems = [deleteItem ,editItems]
     menu.arrowDirection = .down
    return menu
}()

（2）在storyboard中创建一个lable 并且在controller中添加事件

self.lable.isUserInteractionEnabled = true
    let longprss : UILongPressGestureRecognizer = UILongPressGestureRecognizer(target: self, action: #selector(ViewController.labAction))
    self.lable.addGestureRecognizer(longprss)

（3）触发方法中设置menu属性

  menuController.setTargetRect(self.lable.bounds, in: self.lable)
    menuController.setMenuVisible(true, animated: true)

（4）第一个重要的地方：是要重写canBecomeFirstResponder（）

     override var canBecomeFirstResponder : Bool {
    return true
}

（5）第二个重要的地方：实现canPerformAction方法

        override func canPerformAction(_ action: Selector, withSender sender: Any?) -> Bool {
    if(action == #selector(self.deleteLine) || action == #selector(self.editRow))
    {
        return true;
        
    }
    else
    {
        return false;
    }
}