Ext columntree 数据为什么不显示

js代码
Ext.onReady(function(){
var treeloader= new Ext.tree.TreeLoader({
dataUrl:'Net0501Action.do?method=queryfgrq',
uiProviders:{
'col': Ext.ux.tree.ColumnNodeUI
}
});
var root=new Ext.tree.AsyncTreeNode({
id : '0',
text : 'root',
draggable : false,// 根节点不容许拖动
expanded : true
});
root.attributes = {
aab300 : '0',
aab301 : '0',
aae043 : '0'
};
var tree = new Ext.ux.tree.ColumnTree({
height: 300,
rootVisible:false,
autoScroll:true,
title: '数据覆盖人群统计',
renderTo: 'ptreegrid2',
columns:[{
header:'地区',
width:120,
dataIndex:'aab300'
}],
loader:treeloader,
root: root
});
tree.on("beforeload",function(node){
var aab300 = node.attributes["aab300"];
var aab301 = node.attributes["aab301"];
tree.loader.dataUrl = "Net0501Action.do?method=queryfgrq&aab300=" + aab300+"&aab301="+aab301;
});
tree.render();
root.expand();
});

后台请求数据返回：
[{aab300:"杭州市"},{aab300:"上城区"},{aab300:"下城区"},{aab300:"江干区"},{aab300:"拱墅区"},{aab300:"西湖区"},{aab300:"滨江区"},{aab300:"萧山区"},{aab300:"余杭区"},{aab300:"桐庐县"},{aab300:"淳安县"},{aab300:"建德市"},{aab300:"富阳市"},{aab300:"临安市"},{aab300:"杭州市市本级"}]

这里我怕代码太多所以tree 的columns 我只写了一列 实际如图示

你的数据里面少了个属性: uiProvider:'col', 你申明了 uiProviders : {
'col' : Ext.tree.ColumnNodeUI
} 但是数据里面没有，所以没显示
{aab300:'杭州市',uiProvider:'col', children:[{
aab300:'001',
uiProvider:'col',
leaf:true
},{
aab300:'002',
uiProvider:'col',
leaf:true
}]}