get the list data first
and then add a list in to
for update every signle value
for(int i=0;i<=dt.rows.count;i++)
{
combox.items.add(dt.rows[0][i].tostring()
}
for bind a datasource to control
combobox1.datasource=dt;
combobox1.displaymemer="col here ";
combobox1.valuemember= "col here";