Extjs4中 gridpanel 获取单元格

1.

listeners:{

                    cellclick: function(table, td, cellIndex, model, tr, rowIndex, e, eOpts){

                //单击单元格事件       

                    }

                }

2.   

    var projCd = Ext.getCmp('costGrid').getStore().getAt(rowIndex).get('projCd');

3.

  grid.getSelectionModel().getSelection()[0].get('fieldname');