Ext.form.ComboBox 动态加载数据后设置下拉选项

.//获取系统配置项下拉列表function GetSysConfigComboBox(groupId, inputName, fieldLabel, value, disabled) {    var store = new Ext.data.Store({        proxy: new Ext.data.HttpProxy({ url: "SysConfigAction.ashx?action=list&groupid=" + groupId }),        reader: new Ext.data.JsonReader(                      { root: "" },                      Ext.data.Record.create(["Value", "Remark"])                      )    });    var combo = new Ext.form.ComboBox({        store: store,        hiddenName: inputName, //提交到后台的input名称        valueField: 'Value',        displayField: 'Remark', //store字段中你要显示的字段，多字段必选参数，默认当mode为remote时displayField为undefine，当select列表时displayField为"text"        mode: 'local', //因为data已经取数据到本地了，所以'local',默认为"remote"，枚举完        triggerAction: 'all', //很重要        emptyText: '请选择...',        editable: false,        fieldLabel: fieldLabel   //设置表单中显示的标签    });    store.on('load', function() { //数据加载完成后设置下拉框值        if (value)            combo.setValue(value);        combo.disabled = disabled;    });    store.load();    return combo;}