// Update record
var fieldName = record.data.keyName;
var fieldValue = http://www.mamicode.com/record.data.keyValue;
record.data.keyValue = "http://www.mamicode.com/要修改的值";

// New record
Ext.data.Record({keyName:‘ups‘,logic:‘=‘,keyValue:‘kv‘,keyType:‘stirng‘});

Extjs record用法例子