public class Person
        {
            public string Name { get; set; }
            public Person(string name)
            {
                Name = name;
            }
        }

private void Form1_Load(object sender, EventArgs e)
        {
            ListBox lstBox = new ListBox();
            lstBox.DataSource = new List<Person> { new Person("Nour"), new Person("Ahmad") };
            lstBox.DisplayMember = "Name";

            //Controls.Add(lstBox);
         
            ToolStripControlHost host = new ToolStripControlHost(lstBox);
            host.AutoSize = false;

            ToolStripDropDown dropDown = new ToolStripDropDown();
            dropDown.AutoClose = false;
            dropDown.AutoSize = false;
            dropDown.Items.Add(host);

            dropDown.Show(this, 0, 0);
        }