使用ext加载树结构时候接受的JSON串如下，
[{
"id": "10211",
"text": "中心",
"leve": 1,
"children": [{
"id": "13f7b495-9967-1031-9a46-b63f19c07715",
"text": "34",
"iconCls": "Equipment-on-cls6"
}, {
"id": "d27b9dd0-c031-4d4c-b366-b7c018626222",
"text": "nvr",
"iconCls": "Equipment-on-cls6"
}, {
"id": "6102c69d-9cdd-1031-918c-93e8d367897b",
"text": "电视墙",
"iconCls": "car"
}],
"leaf": "false",
"iconCls": "UserGroup-icon-cls",
"superId": "-1"
}]
但是界面上却只是显示 中心 节点，下面的children 显示不出来，求指点。。。
