Observer-intermediary design mode (non-delegate implementation mode) and Observer Design Mode

Observer-intermediary design mode (non-delegate implementation mode) and Observer Design Mode

Implemented through interfaces to achieve loose coupling.

Main form

public partial class mainform : Form    {        public mainform()        {            InitializeComponent();        }        private void butMessage_Click(object sender, EventArgs e)        {            childform1 c1 = new childform1();            c1.Show();            childform2 c2 = new childform2();            c1.messageonList.Add(c2);            c2.Show();            childform3 c3 = new childform3();            c1.messageonList.Add(c3);            c3.Show();        }    }

Subform 1

Public partial class childform1: Form {public childform1 () {InitializeComponent (); messageonList = new List <ImessageOn> ();} // put this set in our observer public List <ImessageOn> messageonList {get; set;} private void butMessage_Click (object sender, EventArgs e) {foreach (var messageon in messageonList) {messageon. receiveMessage ("James ");}}}

Subforms 2 and 3

public partial class childform2 : Form,ImessageOn    {        public childform2()        {            InitializeComponent();        }        public void ReceiveMessage(string str)        {            this.textMessage.Text = str + " " + DateTime.Now.ToString();        }    }