ExtJS Combobox 如何改变下拉列列宽问题

Combobox 默认显示 list和edit 一样宽。 如何让下拉列表更宽些呢? 可以使用expand event.

comboPurchaseOrder = new Ext.form.ComboBox({
        //cls: 'x-mycombo-list',
        tpl: resultTpl,
        store: PurchaseOrderStore,
        displayField: 'PurchaseOrder',
        valueField: 'PrimaryKey',
        typeAhead: false,
        mode: 'local',
        triggerAction: 'all',
        selectOnFocus: true,
        value: '',
        120,
        itemSelector: 'div.search-item',
        applyTo: 'ddlPurchaseOrder'
    });
    comboPurchaseOrder.on('expand', function(comboBox) {
        comboBox.list.setWidth('240px'); //auto
        comboBox.innerList.setWidth('auto');
    }, this, { single: true });

简单实用，try it.