ExtJS GridPanel只显示一条记录

问题：在做一个项目时，后台通过json传入前台数据，但是后台打印的是三条数据，前台只显示一条数据。

json格式如下：

{"sqksm":[{"carbonLayerNum":1,"endArea":0,"endTime":"","id":0,"shiHouEndArea":0,"shiHouStartArea":0,"startArea":0,"start
Time":"","treeId":32,"treeName":"黑松","tree_lm_ksm_rate":0},{"carbonLayerNum":2,"endArea":0,"endTime":"","id":0,"shiHouEn
dArea":0,"shiHouStartArea":0,"startArea":0,"startTime":"","treeId":33,"treeName":"紫杉","tree_lm_ksm_rate":0},{"carbonLaye
rNum":2,"endArea":0,"endTime":"","id":0,"shiHouEndArea":0,"shiHouStartArea":0,"startArea":0,"startTime":"","treeId":34,"
treeName":"铁杉","tree_lm_ksm_rate":0}],"total":3}

 前台代码如下：

var jixian_kusismu_store = new Ext.data.JsonStore({
		url:'listXiangMuShiQianKusiMu.do',/**请求用户数据库*/
		totalProperty : 'total',
		root:'sqksm',
		fields : [/**用到的json域*/
				{
					name : 'id'
				},{
					name:'treeId'
				},{
					name:'treeName'
				},{
					name:'carbonLayerNum'
				},{
					name:'startTime'
				},{
					name:'endTime'
				},{
					name: 'tree_lm_ksm_rate'
				},{
					name:'startArea'
				},{
					name:'endArea'
				}
				]
		});
		jixian_kusismu_store.load({
					params : {
						start : 0,
						limit : 20
					}
		});

 

细心的人可发现：传回的数据的json数据的id都是0，导致extjs无法找到主键，这是是extjs的一个bug。 在grid的getStore的load的回调函数中，用getCount到到的是一条数据。也就是服务端返回了多条数据，但是extjs只解释了一条数据，同样，extjs也不能解析符合主键。

解决方法：回传数据id为主键即可。

{"sqksm":[{"carbonLayerNum":1,"endArea":0,"endTime":"","id":12,"shiHouEndArea":0,"shiHouStartArea":0,"startArea":0,"star
tTime":"","treeId":32,"treeName":"黑松","tree_lm_ksm_rate":0},{"carbonLayerNum":2,"endArea":0,"endTime":"","id":13,"shiHou
EndArea":0,"shiHouStartArea":0,"startArea":0,"startTime":"","treeId":33,"treeName":"紫杉","tree_lm_ksm_rate":0},{"carbonLa
yerNum":2,"endArea":0,"endTime":"","id":14,"shiHouEndArea":0,"shiHouStartArea":0,"startArea":0,"startTime":"","treeId":3
4,"treeName":"铁杉","tree_lm_ksm_rate":0}],"total":3}