datagridviewcolumn - C# DataGridView: Value disappearing in dynamic added column -

i coming across strange or maybe way works , lack of understand of how datagridview works. dynamically adding column when click on button

    private void btnassign_click(object sender, eventargs e)     {         if (!gvdata.columns.contains("departmentid"))         {             datagridviewtextboxcell cell = new datagridviewtextboxcell();             datagridviewcolumn dc = new datagridviewcolumn();             dc = new datagridviewtextboxcolumn();             dc.headertext = "departmentid";             dc.name = "departmentid";             dc.celltemplate = cell;             gvdata.columns.add(dc);         }         foreach(datagridviewrow row in gvdata.selectedrows)         {             row.cells["departmentid"].value = getselectedvalues(clbdept);         }     } 

first checks if departmentid column in datagridview (dgv). if not create new datagridviewtextboxcolumn , sets appropriate settings. adds values cells. far good... weird things... when sort column, data in 'departmentid' column disappears. data disappears in columns dynamically create. have use save method or something?

instead of adding data directly datagridview need add column datasource , reassign datasource datagridview. resolve sorting issue.