前台：

var provinceStore = new Ext.data.Store({  
    proxy: new Ext.data.HttpProxy({ url: basePath + "/stationManage/station_getProvinceJSON.action" }),  
    reader: new Ext.data.JsonReader(  
                  { root: "" },  
                  ["PROVINCEID", "PROVINCENAME"]  
                  )  
});  


//选择省市
var provinceIDadd = new Ext.form.ComboBox({
	anchor : '98%',
	id:'provinceIDadd',
	name : "provinceIDAdd1",
	hiddenName : "provinceID",
	displayField : "PROVINCENAME",
	valueField : "PROVINCEID",
	blankText : '请选择站点所属省份',
	emptyText : '请选择站点所属省份',
	fieldLabel : '站点所属省份',
	allowBlank : false,
	editable : false,
	triggerAction : 'all',
	store :provinceStore ,
	forceSelection : true,
	mode : 'local',
	selectOnFocus : true
})
provinceStore.load();

public class StationAction extends BaseAction {

	private List<Map<String, Object>> provinceList;
	public void setProvinceList(List<Map<String, Object>> provinceList) {
		this.provinceList = provinceList;
	}

	public List<Map<String, Object>> getProvinceList() {
		return provinceList;
	}
	public String getProvinceJSON(){
		String sql="SELECT PK_ID PROVINCEID,NAME PROVINCENAME FROM T_DICT_DISTRICT A WHERE A.DISTRICT_LEVEL=20";
		provinceList= stationService.findBySQL(sql);
		return "json_getProvinceList";
	}
}

<result name="json_getProvinceList" type="json" >
	       	<param name="root">provinceList</param>
</result>

加载静态数据的下拉选择框

var dataType=[['0','8列'],['1','38列'],['2','21列']];
var dataTypeStore = new Ext.data.SimpleStore({
	fields: ['dataTypeID', 'dataTypeName'],
	data : data
});

var dataTypedd = new Ext.form.ComboBox({
	anchor : '98%',
	id:'dataTypeadd',
	name : "dataTypeAdd1",
	hiddenName : "dataType",
	displayField : "dataTypeName",
	valueField : "dataTypeID",
	blankText : '请选择数据格式',
	emptyText : '请选择数据格式',
	fieldLabel : '数据格式',
	allowBlank : false,
	editable : false,
	triggerAction : 'all',
	store :unitStore ,
	forceSelection : true,
	mode : 'local',
	selectOnFocus : true
})