Dynamically added Easy Menu persists on PostBack. We need to use Page_Load and Page_Init events. In the Page_Init method we will create the Easy Menu, set the id and add it to the page's control list. On Page_Load event, if there is no PostBack (!Page.IsPostBack), we will populate the Easy Menu with items and properties. After a postback, Easy Menu is loaded automatically from ViewState.

In page class:

  protected EasyMenu em_1;

Here is the code for Page_Load:

  void Page_Load(object sender, EventArgs e) 
  {
    if (!Page.IsPostBack)
    {
      em_1.AttachTo = "item1";
      em_1.AddItem(new MenuItem("menuItem1", "SubItem 1", "", "", "", 
		"alert('Item 1 - SubItem 1')"));
      em_1.AddItem(new MenuItem("menuItem2", "SubItem 2", "", "", "", 
		"alert('Item 1 - SubItem 2')"));
        ...
        
    }
  }

And the code for Page_Init:

  void Page_Init(object sender, EventArgs e) 
  {
    em_1 = new EasyMenu();
    em_1.ID = "Easymenu1";

    Page.Controls.Add(em_1);
  }

Now we need to add a control that posts back the page. For example, a button:

<asp:Button id="Button1" runat="server" Text="PostBack"></asp:Button>


You will notice that even after pressing the button (posting back the page to the server), the Easy Menu will still be populated with its items and properties.