public enum UserLevel
        {          
            Commmon = 0,
            Administrator,
            Developer
        }

        private void Method1()
        {
            comboBox1.DataSource = System.Enum.GetNames(typeof(UserLevel));
            comboBox1.SelectedIndex = 
　　　　　　　　　　　　　comboBox1.FindString(UserLevel.Commmon.ToString());            
        }

        private void Method2()
        {
            foreach (var v in typeof(UserLevel).GetFields())
            {
                if (v.FieldType.IsEnum == true)
                {
                    this.comboBox2.Items.Add(v.Name);
                }
            }
            this.comboBox2.SelectedIndex = 1;
        }

            
            UserLevel testenum = (UserLevel)Enum.Parse(typeof(UserLevel), comboBox1.SelectedItem.ToString(), false);