参考这个demo,监听oncellbeginedit http://www.miniui.com/demo/index.html#src=datagrid/editable.html
function OnCellBeginEdit(e){
var field=e.field;
var record=e.record;
var time1=record.时间;
var today=new Date()
f(field=="你combobox列"&&time1.getTime()<today.getTIme()){
e.cancel=true;
}
}