Ext.data.TreeStore展开节点重复load

showTreeData = [
{
id:0,
text:‘123‘,
leaf:true
},
{
id:1,
text:‘234‘,
children:[{
　　id:2,
　　text:‘234-1‘,
　　leaf:true
}],
expanded:false
}
];
 var ststoredata = Ext.encode(showTreeData);
    var ststore = Ext.create(‘Ext.data.TreeStore‘, { 
        model : ‘showTree‘,
        autoLoad : false,
        clearOnLoad:true,
        clearRemovedOnLoad:true,
        proxy: {
            type: ‘ajax‘,
            url: ‘../FileMng.php?xOper=showtree&datalist=‘+ ststoredata,//‘../FileMng.php?xOper=test&start=0&limit=1000&dir=E:‘+VSC_AppRootPath,‘treegrid.json‘
            reader: {
                type: ‘json‘
                root: ‘rs‘,
                totalProperty: ‘count‘
            }

    }

else if ( $xOper == "showtree") {//获取文件列表
    //设初值datalist
    $restr = "{count:0}";
    $datalist = json_decode($_GET["datalist"]);
    $count = $_GET["count"];
    $array = array(
            "count" => $count,      //总记录数
            "rs" => $datalist        //记录集
    );
    $restr = json_encode ($array);
     $count = 0;
    print $restr;
}

showTreeData = [
{
id:0,
text:‘123‘,
leaf:true
},
{
id:1,
text:‘234‘,
children:[{
　　id:2,
　　text:‘234-1‘,
　　leaf:true
}],
expanded:false
}
];
    var ststoredata = Ext.encode(showTreeData);
    var ststore = Ext.create(‘Ext.data.TreeStore‘, { 
        model : ‘showTree‘,
        autoLoad : false,
        clearOnLoad:true,
        clearRemovedOnLoad:true,
        proxy: {
            type: ‘ajax‘,
            url: ‘../FileMng.php?xOper=showtree&datalist=‘+ ststoredata,//‘../FileMng.php?xOper=test&start=0&limit=1000&dir=E:‘+VSC_AppRootPath,‘treegrid.json‘
            reader: {
                type: ‘json‘
//                root: ‘rs‘,　　//不使用自定义根节点
//                totalProperty: ‘count‘ 
            }

    }

else if ( $xOper == "showtree") {//获取文件列表
    //设初值datalist
    $restr = "{count:0}";
    $datalist = json_decode($_GET["datalist"]);
    $count = $_GET["count"];
    $array = array(
            "count" => $count,      //总记录数
            "rs" => $datalist        //记录集
    );
    $restr = json_encode ($datalist);//不使用array,直接使用datalist返回
//     $count = 0;
    print $restr;
}