ExtJs 4.2 treePanel 点击树节点 传送参数到后台（多个参数）

//***********************************************左边树开始***********************************************
//分组树Store
var treeStore = Ext.create('Ext.data.TreeStore', {
    proxy: {
        type: 'ajax',
        url: "/Handler/StorePositionLayoutHandler.ashx?func=getbystorestorepositionlist&format=list"
    },
    autoLoad: false,
    fields: ['text', 'id', 'leaf', 'SPLId', 'SPLName', 'StoreId', 'Level1', 'Level2', 'Level3', 'levelType'],
    reader: {
        type: "json",
        root: ''
    },
    extraParams: {
        SPLId: '',
        StoreId: '',
        Level1: '',
        Level2: '',
        Level3: '',
        levelType: '',
    }
});
//分组树
var treePanel = Ext.create('Ext.tree.Panel', {
    store: treeStore,
    border: false,  //边框
    enableDD: true,
    rootVisible: false,  //隐藏根节点
    useArrows: true, //树节点使用箭头
    containerScroll: true,
    collapsible: false,
    autoScroll: false,
    title: '货位信息列表',
    columns: [{
        xtype: 'treecolumn',
        text: '货位层次',
        dataIndex: 'text',
         150,
        sortable: true
    }, {
        text: '货位名称',
        dataIndex: 'SPLName',
        flex: 1,
        sortable: true
    }],
    //点击目录树+前 给root参数赋值  
    listeners: {
        //树列表单击，取值赋值给id:xxxx的文本框  
        itemclick: function (node, record, item, index, event, eOpts) {
            //给右侧页面赋值 开始
            var id = record.data.id;
            var text = record.data.text;
            var SPLId = record.data.SPLId;
            var SPLName = record.data.SPLName;
            var StoreId = record.data.StoreId;

            BelowForm.setTitle('当前货位：' + text + '' + SPLName);

            BelowForm.form.findField('SPLId').setValue(SPLId);
            BelowForm.form.findField('SPLName').setValue(SPLName);
            //给右侧页面赋值 结束  
        },
        //点击目录树+前 给root参数赋值  
        beforeitemexpand: function (record, eOpts) {
            if (treePanel != undefined) {
                var root = treePanel.store.getProxy();
                root.extraParams.SPLId = record.data.SPLId;
                root.extraParams.StoreId = record.data.StoreId;
                root.extraParams.Level1 = record.data.Level1;
                root.extraParams.Level2 = record.data.Level2;
                root.extraParams.Level3 = record.data.Level3;
                root.extraParams.levelType = record.data.levelType;
            }
        }
    }
    //singleExpand:true   //展示单个子节点，其它的子节点合并。
});
//treePanel.expandAll(); //展开所有节点
treePanel.collapseAll(); //关闭所有节点

//***********************************************左边树结束***********************************************