how to add an item to a combobox which will already bound to database

Its Pretty Simple

You have to do nothing

when you bound your combobox from the database then for adding a new item into that combobox you must change the datasource.

Let's see an example to make it better.


Suppose cb1 is your combobox and the field name is District in Database.

when you bound it from databse it shows name of district, Now you want to add some run time values.

from Database you set the datasource like

cb1.DataSource=ds.Tables[0]  or   cb1.DataSource=dt;    // where dt=ds.Tables[0];
cb1.DisplayMember="District";

Go with the code as below:

DataTable Dt1=new DataTable();
Dt1.Columns.Add("District");
Dt1.Rows.Add("Delhi");
Dt1.Rows.Add("Haryana");

Now

dt.Merge(Dt1);

again set like

cb1.DataSource=dt;    
cb1.DisplayMember="District";

This will add two new Districts named Delhi and Haryana in ComBoBox

This will solve your Problems

Clear the combox first add new