public interface IUserAdd {        event EventHandler UserAddEvent;        string UserName { get; set; }        string UserAge { get; set; } }

public partial class UserAdd : UserControl, IUserAdd {        public event EventHandler UserAddEvent;        public string UserName        {            set { this.txbName.Text = value; }            get { return this.txbName.Text; }        }        public string UserAge        {            set { this.txbAge.Text = value; }            get { return this.txbAge.Text; }        }        public UserAdd()        {            InitializeComponent();        }        private void btnAdd_Click(object sender, EventArgs e)        {           if (UserAddEvent != null) UserAddEvent(this, e);        }    }

public class UserAddPresenter:IPresenter {        private readonly IUser _model;        private readonly IUserAdd _view;        private readonly ApplicationFacade _facade = ApplicationFacade.Instance; //这里的facade是Presenter之间通信用的，详细可以看完整代码       //Presenter构造函数中，将view和model作为参数传入        public UserAddPresenter(IUser model, IUserAdd view)        {            _model = model;            _view = view;            WireUpViewEvents();        }        private void WireUpViewEvents()        {            _view.UserAddEvent += _view_UserAdd;        }       //当view的UserAdd事件触发，取得UI中的数据，调用model逻辑处理，添加新用户。      //同时发送User_ADDED消息到系统中(系统中其它UI部分接收消息，比如这里的DataGrid，它接收到User_ADDED之后，会刷新)        private void _view_UserAdd(object sender, EventArgs e)        {            var user = new User                       {                           Name = _view.UserName,                           Age = Convert.ToInt32(_view.UserAge)                       };            _model.AddItem(user);            _facade.SendNotification(ApplicationFacade.USER_ADDED);        } }