Hello tuoc le,

Could you please take a look in our online documentation. There you could find information how to bind your control to different datasources:

http://help.infragistics.com/Help/NetAdvantage/WinForms/2012.2/CLR4.0/html/WinCombo_Binding_WinCombo_to_a_Data_Table.html 

http://help.infragistics.com/Help/NetAdvantage/WinForms/2012.2/CLR4.0/html/WinCombo_Binding_WinCombo_to_Data_Using_LINQ_to_SQL.html

http://help.infragistics.com/Help/NetAdvantage/WinForms/2012.2/CLR4.0/html/WinCombo.html 

tuoc le said:

I would like to know to to bind the control to a datasource at runtime

One possible approach could be if you are using:

ultraCombo1.DataSource = DataSet1;

ultraCombo1.DataMember ="Table1";

ultraCombo1.DisplayMember ="Column1";

ultraCombo1.ValueMember ="Column0";

Let me know if you have any questions.

REgards