How to set first index as blank in combobox

Question

I have a combobox that is bound with a datasource. In this combobox I have to add a blank field at index 0.

I have written following code for getting records.

 public List<TBASubType> GetSubType(int typ)
        {
            using (var tr = session.BeginTransaction())
            {
                try
                {
                    List<TBASubType> lstSubTypes = (from sbt in session.Query<TBASubType>()
                                                    where sbt.FType == typ
                                                    select sbt).ToList();


                    tr.Commit();
                    return lstSubTypes;
                }
                catch (Exception ex)
                {
                    CusException cex = new CusException(ex);
                    cex.Write();
                    return null;
                }
            }
        }

After this it bind with combobox with data binding source as below code.

M3.CM.BAL.CM CMobj = new M3.CM.BAL.CM(wSession.CreateSession());
                lstSubTypes = CMobj.GetSubType(type);
                this.tBASubTypeBindingSource.DataSource = lstSubTypes;

Answer 1

If you just want to select nothing initially, you can use

comboBox1.SelectedIndex=-1;