extjs如何控制左侧菜单默认不打开第一个，这是整个左侧菜单的js

[两宙]

Ext.namespace('Ext.app.frame');
Ext.app.frame.LeftPanel = Ext.extend(Ext.Panel, {
//初始化加载的菜单ID
welcomeMenuId : customInfo['defaultTopMenuId'],
//项目路径
context : customInfo['context'],
//构造方法
constructor : function(_cfg) {
Ext.apply(this, _cfg);
},
wizCount :0,
readyCount :0,
//初始化
initialize:function(_cfg){
//生成左侧面板
Ext.app.frame.LeftPanel.superclass.constructor.call(this, {
id : 'accordion-panel',
iconCls : 'icon-nav',
layout : 'accordion',
region : 'west',
margins : '10 10 2 2',
width : 220,
bodyStyle : 'background-color:#DFE8F6',
collapsible : true,
split : false,
layoutConfig : {
animate : true
}
});
//左侧面板首次设置内容
var welcomeMenu = {menuId:this.welcomeMenuId, text:customInfo['defaultTopMenuName']};
this.setContent(welcomeMenu);
},
//设置面板内容（主要方法）
setContent:function(currMenu){
var aim = Ext.getCmp('accordion-panel');
var currScope = this;
aim.removeAll(true);
if(currMenu!=undefined && currMenu.menuId!=undefined){
var _temptitle = currMenu.text || "";
aim.setTitle(_temptitle);
//添加扩展，如果菜单配置URL为IFM：开头的话， 表示为做菜单是扩展的菜单，嵌入IFRAME显示URL
var _tempURL = currMenu.menuURL|| "";
if(_tempURL!=""){
aim.body.update("");
}
if(_tempURL.indexOf("IFM:")>-1){
_tempURL = _tempURL.substring(4);
aim.body.update("<IFRAME width=\"100%\" height=\"100%\" FRAMEBORDER=0 SCROLLING=auto SRC='"+_tempURL+"'></IFRAME>");
if(currScope.ownerCt.menuBar){
currScope.ownerCt.menuBar.enableAllButtons();
}
return;
}
var requesturl = this.context+'/menu!topLeft.lxd?menuId='+currMenu.menuId;
Ext.Ajax.request({
url: requesturl,
success: function(response) {
//获取响应的json字符
json = Ext.decode(response.responseText);
if(json!=undefined && json.length!=undefined){
currScope.wizCount = json.length;
currScope.readyCount = 0;
for(var i=0;i<json.length;i++){
var left = json[i];
var title = left.text;
var id = left.id;
var url;
if(left.menuUrl!=undefined){
url=left.menuUrl.substring(0,4)=="IFM:"?left.menuUrl.substring(4):left.menuUrl;
}
var target = left.urltarget;
var panel;
if(url && target=="leftFrame"){
if(url.substring(0,4)!="http"){
url = customInfo['context']+"/"+url;
}
panel = new Ext.Panel({
id : id,
title : title,
layout: 'fit',
border: false,
iconCls : 'icon-nav',
items : [
new Ext.ux.IFrameComponent({
id: 'menu_iframe_'+id,
collapsed:true,
url: url
})
]
});
}else{
panel = new Ext.app.frame.WizardPanel({
id : id,
title : title,
group : 'group',
checked : 'checked',
dataUrl : '/menu!downLeft.lxd?menuId=' + id
});
}
aim.add(panel);
aim.doLayout();
currScope.readyCount++;
if(currScope.readyCount == currScope.wizCount){
if(currScope.ownerCt.menuBar){
currScope.ownerCt.menuBar.enableAllButtons();
}
}
}
}else{
Ext.Msg.alert('错误','读取菜单错误！');
if(currScope.ownerCt.menuBar){
currScope.ownerCt.menuBar.enableAllButtons();
}
}
},
failure: function(){
Ext.Msg.alert('错误','连接服务器超时！');
if(currScope.ownerCt.menuBar){
currScope.ownerCt.menuBar.enableAllButtons();
}
}
});
}
}

});
Ext.app.frame.WizardPanel = Ext.extend(Ext.Panel, {
context : customInfo['context'],
iconCls : 'icon-nav',
border : false,
rootVisible : false,
autoScroll : true,
dataUrl : null,
//buttons : {},
tree : null,
constructor : function(_cfg) {
Ext.apply(this, _cfg);
var _tree = new Ext.tree.TreePanel({
iconCls : 'icon-nav',
border : false,
rootVisible : false,
loader : new Ext.tree.TreeLoader({
// dataUrl : context +
// '/jsonTree!wizardJson.lxd'
dataUrl : this.context + this.dataUrl
}),

style : {
padding : 3
},
root : new Ext.tree.AsyncTreeNode({
text : _cfg.title || this.title,
// ,
// children : _cfg.childrens || null
expanded : false

}),
listeners : {
'click' : function(n) {
try {
if (n.leaf) {
if(n.attributes.urltarget=='_blank'){
var openURL = n.attributes.menuUrl;
if(openURL.substring(0,4)!="http"){
openURL = customInfo['context']+"/"+openURL;
}
window.open(openURL);
}else{
this.onNodeClick(n.id, n.text,n.attributes.menuUrl);
}
}else{
if(n.attributes.menuUrl){
if(n.attributes.urltarget=='_blank'){
var openURL = n.attributes.menuUrl;
if(openURL.substring(0,4)!="http"){
openURL = encodeURI(customInfo['context']+"/"+openURL);
}
window.open(openURL);
}else{
this.onNodeClick(n.id, n.text,n.attributes.menuUrl);
}
}
}
} catch (e) {
}
},
scope : this
}

});


this.tree = _tree;


Ext.app.frame.WizardPanel.superclass.constructor.call(this, {
margins : '2 0 5 5',
layout : 'anchor',
items : [this.tree]

});

},
afterRender : function(){
Ext.app.frame.WizardPanel.superclass.afterRender.call(this);
},
// 树图刷新
tree_refresh : function(menuId) {
this.refresh(menuId);
},
ReturnValue : function(title, value) {
Ext.Msg.show({
title : title,
msg : value,
icon : Ext.Msg.INFO,
minWidth : 210,
buttons : Ext.Msg.OK
});
},
// 为叶子菜单增加对应点击事件，调用链接对应的页面
onNodeClick : function(id,name,menuUrl) {

var tabPanel = Ext.getCmp("content-panel");
var allItems = tabPanel.items.items;
var tabPage;
var b = true;
var delegateArray = {'id':id,'name':name,'menuUrl':menuUrl};
if(menuUrl.substring(0,4)!="http"){
menuUrl = encodeURI(customInfo['context']+"/"+menuUrl);
}
for (var i = 0; i < allItems.length; i++) {
var _text = allItems[i].title;
if (_text == name) {
tabPage = allItems[i];
// 设置当前tab页
tabPanel.setActiveTab(tabPage);
b = false;
// 重新刷新当前活动tab
Ext.get('f_'+name).dom.src=menuUrl;
break;
}
}
if (b) {
Ext.Ajax.request({
url : menuUrl,// 增加传递参数，处理暂停流程
success : this.showNodeTabPanel.createDelegate(this, delegateArray, true),// 调用异步函数，传递对应参数
failure : this.menuError,
scope : this
});
}
},
// 为叶子菜单增加对应点击事件，调用链接对应的页面
showNodeTabPanel : function(result, thisObj, delegateArray) {
var text = result.responseText;
var tabPanel = Ext.getCmp("content-panel");
var _url = delegateArray['menuUrl'];
if(_url.substring(0,4)!="http"){
_url = encodeURI(customInfo['context']+"/"+_url);
}
tabPage = tabPanel.add({
title : delegateArray['name'],
html : "<iframe id='f_" + delegateArray['name'] + "' scrolling='auto' frameborder='0' width='100%' height='100%' src='"
+ _url + "'></iframe>",
closable : true
});
tabPanel.setActiveTab(tabPage); // 设置当前tab页
},
refresh : function(topMenuId) {
var loader = new Ext.tree.TreeLoader({
dataUrl : this.context + '/menu!left.lxd?menuId=' +topMenuId
});
loader.load(this.tree.root);
this.tree.root.expand(true);//不起作用？
},
expandTreeNodes: function(){
var tree = this.tree;
tree.root.expand(true);
}
});


//根据组件ID获得相应的组件
function getComponent(id){
return Ext.getCmp(id);
}

//tab数量大于6个时，显示的提示信息
function alarmMessage(){
Ext.Msg.alert("提示信息","最多打开6个tab，请关闭无用页面");
}