ext tree

<script type="text/javascript">    Ext.onReady(function(){        var tree= new Ext.tree.TreePanel({            el:'tree',            loader:new Ext.tree.TreeLoader()        });                var root = new Ext.tree.AsyncTreeNode({            text:'我是根',            children:[{                text:'01',qtip:'我是鼠标提示',//如果有qtip属性,则必须要有Ext.QuickTips.init()这句话                children:[{                    text:'01-01',                    leaf:true   //这里为true代表他下面已经没有子节点，不需要加载出来                },{                    text:'01-02',                    children:[{                        text:'01-02-01',                        leaf:true                    },{                        text:'01-02-02',                        leaf:true                    }]                },{                    text:'01-03',                    leaf:true,                    href:"http://www.baidu.com",//通过点击节点，可以链接到一个地址                    hrefTarget:'_blank'                   }]            },            {                text:'02',                leaf:true,                icon:'user_female.png'  //自定义节点的图标            }]        });        tree.setRootNode(root);        tree.render();                tree.on('dblclick',function(node){            Ext.Msg.alert('您刚刚双击了',node.text);        });                //右键菜单        var contextmenu = new Ext.menu.Menu({            id:'thecontextmenu',            items:[{                text:'选择',                 handler: function() {                                              alert('你选择的是=' + tree.getSelectionModel().getSelectedNode().text + " 结点");                      }            }]        });                //右键菜单显示        tree.on('contextmenu',function(node,e){             e.preventDefault();            node.select();//节点进入选中状态            contextmenu.showAt(e.getXY());        });                tree.on('click',function(node){            Ext.Msg.show({                title:'提示',                msg:'您点击了:'+node,                animEl:node.ui.textNode            });        });                root.expand();        Ext.QuickTips.init(); //初始化接点提示        tree.expandAll();//展开所有节点    });    </script>