EXT GridPanel獲取某一單元格的值

//EXT GridPanel獲取某一單元格的值
listeners:{
'cellclick':function(grid, rowIndex, columnIndex, e){
editCell_row = rowIndex; 
editCell_col = columnIndex;
var record = grid.getStore().getAt(rowIndex);
var fieldName = grid.getColumnModel().getDataIndex(columnIndex);
var data = record.get(fieldName);
}
}