为什么EditorGridPanel 修改一个，其它的列的renderer全执行呀？


//定义列模型
var cm = new Ext.grid.ColumnModel([
{header: "订单编号", dataIndex: "ID", width: 60, 
editor: new Ext.grid.GridEditor(new Ext.form.NumberField({allowBlank: false}))},
{header: "下单日期", dataIndex: "DATE",width: 140, 
renderer: Ext.util.Format.dateRenderer("Y-m-d"),
editor: new Ext.grid.GridEditor(new Ext.form.DateField({
format: "Y-m-d"
}))},
{header: "收货人姓名", dataIndex: "NAME",width: 120,
editor: new Ext.grid.GridEditor(new Ext.form.TextField())},
{header: "收货人地址", dataIndex: "ADDRESS",id: "ADDRESS",
editor: new Ext.grid.GridEditor(new Ext.form.TextField())},
{header: "交易银行", dataIndex: "BANK",width: 120,
editor: new Ext.grid.GridEditor(new Ext.form.ComboBox({
store: new Ext.data.SimpleStore({
fields: ["value", "text"],
data: banks
}),
displayField: "text",
valueField: "value",
mode: "local",
triggerAction: "all",
readOnly: true,
emptyText: "请选择银行"
}))},
{header: "快递", dataIndex: "ISFAST",width: 70, 
renderer: function(v){ alert(v);return v ? "快递" : "非快递"},
editor: new Ext.grid.GridEditor(new Ext.form.Checkbox())}
]);
 
 
为什么我改每一行，都执行快递的renderer呀？