Ext.define('Beam', {
            extend: 'Ext.data.Model',
            fields: [
                {name: 'id', type: 'int'},
                {name: 'name',  type: 'string'},
            ]
        });

var beamSearch = Ext.create('Ext.data.Store', {
            model: 'Beam',
            proxy: {
                type: 'ajax',
                api:{
                    read:'../loadBeamStore.action'
                },
                reader: {
                    type: 'json',
                    root: 'beams'
                }
            },
            autoLoad: false
});

 

combo內容如下

{
    xtype:'combo',
    fieldLabel: '名稱',
    store: beamSearch,
    itemId:'beamSearch',
    queryMode: 'local',
    displayField: 'name',
    valueField: 'id',
    forceSelection:true,
    editable : false,
    hideTrigger : false,// 隱藏微調按鈕
    allowBlank : false,
    value:0,
    listeners:{
      'expand':function(th){
           beamSearch.load();
       }
    }            
}
 

後臺action若定義了success變數，則前端返回的success必須設為true，否則無法加載出store。

private List<Beam> beams = new ArrayList<Beam>();
private boolean success;//定義了success變數


@Action(value = "loadBeamStore", results = { @Result(type = "json") })
   public String loadBeamStore(){
        int num = 23;
        for(int i = 1; i < num; i++){
            Beam beam = new Beam();
            beam.setId(i);
            beam.setName("option "+i);
            beams.add(beam);
        }
        this.success = true;//則必須返回true
        return SUCCESS;
    }