ext怎么在panel里面增加一棵树?

Ext.onReady(function() {
var tree = new Ext.tree.TreePanel({
title :"test",
width :300,
height :450,
useArrows :true,// 是否使用箭头样式
autoScroll :true,// 滚动条
animate :true,// 展开,收缩动画
rootVisible :false,// 根节点是否可见
lines :false,// 禁止显示树的虚线
root :new Ext.tree.AsyncTreeNode({
text :"all",
children :[{
text :"aaa",
checked :false,
children :[{
text :"bbb",
checked :false,
children :[{
text :"新增",
id :"aaa",
checked :false,
leaf :true
},{
text :"修改",
checked :false,
leaf :true
},{
text :"删除",
checked :false,
leaf :true
},{
text :"刷新",
checked :false,
leaf :true
}]
},{
text :"ddd",
checked :false,
children :[{
text :"新增",
checked :false,
leaf :true
},{
text :"修改",
checked :false,
leaf :true
},{
text :"删除",
checked :false,
leaf :true
},{
text :"刷新",
checked :false,
leaf :true
}]
}]
},{
text :"ccc",
checked :false,
children :[{
text :"eee",
checked :false,
children :[{
text :"新增",
checked :false,
leaf :true
},{
text :"修改",
checked :false,
leaf :true
},{
text :"删除",
checked :false,
leaf :true
},{
text :"刷新",
checked :false,
leaf :true
}]
}]
}]
})
})
var views = new Ext.Panel({
width :300,
height :450,
border :true,
renderTo :Ext.getBody(),
items :[tree],
tbar :[{
text :"保存",
icon :"/hims/resources/images/icons/save.gif",
cls :"x-btn-text-icon",
handler :function() {
}
},"-",{
text :"刷新",
icon :"/hims/resources/images/icons/reload-green.png",
cls :"x-btn-text-icon",
handler :function() {
}
}]
});
})

extjs里面的组件是可以嵌套添加的
1.静态的： 直接放到items:[] 下就可以
2.动态的： 可以调用add()方法添加, 添加完成后，重新布局。