MenuItemCollection class

[AspNetHostingPermissionAttribute(SecurityAction.LinkDemand, Level = AspNetHostingPermissionLevel.Minimal)]
[AspNetHostingPermissionAttribute(SecurityAction.InheritanceDemand, Level = AspNetHostingPermissionLevel.Minimal)]
public class MenuItemCollection : CollectionBase

public override void CreateWebPartMenu()
{
    // Declare variables for menu items.
    MenuItem ParentItem;
    MenuItem Item1;
    MenuItem Item2;

    // Create three menu items:
    // One parent item, and two submenu items.

    // Create the parent item.
    ParentItem = new MenuItem("ParentItem", "", "ParentItemID");

    // Create a submenu item with a server event on click.
    Item1 = new MenuItem("Item1", "Item1ID", new EventHandler(EventHandlerForItem1));

    // Create a submenu item with a client event on click. 
    Item2 = new MenuItem("Item2", "javascript:alert('Item2 was clicked');", "Item2ID");

    // Add the submenu items to the parent item.
    ParentItem.MenuItems.Add(Item1);
    ParentItem.MenuItems.Add(Item2);

    // Add the parent item after the "Modify Shared/Personal Web Part"
    // command in the default menu. 

    // Retrieve the index of the "Modify Shared/Personal Web Part" 
    // command.
    int EditIndex = this.WebPartMenu.MenuItems.IndexOf(this.WebPartMenu.MenuItems.ItemFromID("MSOMenu_Edit"));

    // Insert the parent item after the "Modify Shared/Personal Web 
    // Part" command.
    this.WebPartMenu.MenuItems.Insert(EditIndex + 1, ParentItem); 

    // Add a separator above the parent item.
    ParentItem.BeginSection = true;

    // Check the "ParentItemIsVisible" custom boolean property to 
    // decide whether to display the parent menu.
    if (this.ParentItemIsVisible == true)
    {
        ParentItem.Visible = true;
    }

    else
    {
        ParentItem.Visible = false;
    }

    // Check the "EnableItem1" custom boolean property to decide which 
    // menu item to enable. 
    // within the parent item.
  if (this.EnableItem1 == true)
    {
        Item1.Enabled=true;
        Item2.Enabled=false;
    }
    
    else
    {
        Item1.Enabled=false;
        Item2.Enabled=true;
    }
}