treecheck里面有好多可用的知识

Ext.namespace("Wsd.fn.common");

Wsd.fn.common.TreeDemo = function() {
    // 树根
    var rootNode = new Ext.tree.AsyncTreeNode({
        id : '0',
        text : '总目录'
    });
    // 树加载器
    var treeLoader = new Ext.tree.TreeLoader({
        dataUrl : 'getTree.jsp'
    });

    // 当选择节点时影响所有子节点
    var nodeSubCheckChange = function(node, bool) {
        if (node) {
            var childNodes = node.childNodes;
            // 选中或取消所有子节点
            if (childNodes && childNodes.length > 0) {
                var folders = new Array();
                for (var i = 0, len = childNodes.length; i < len; i++) {
                    if(childNodes[i].getUI().checkbox){
                        childNodes[i].getUI().checkbox.checked = bool;
                    }
                    // 递归调用将影响所有的子节点
                    if (childNodes[i].leaf == false) {
                        var tmpNode = childNodes[i]; 
                        folders[folders.length] = tmpNode;
                    }
                }
                for(var i=0,len=folders.length;i<len;i++){
                    var tmpNode = folders[i];
                    tmpNode.getOwnerTree().fireEvent('checkchange', tmpNode, bool);
                }
            }
        }
    };
    // 当选择节点时影响所有的父节点
    var nodeParCheckChange = function(node, bool) {
        if (node) {
            // 对所有的父节点进行选中与取消
            var parentNode = node.parentNode;
            while (parentNode) {
                if(parentNode.getUI().checkbox){
                    parentNode.getUI().checkbox.checked = bool;
                }
                parentNode = parentNode.parentNode;
            }
        }
    };
    
    //获取所有的node
    var getNodes = function(treePanel){
        var startNode = treePanel.getRootNode();
        var r = [];
        var f = function(){
                r.push(this);
        };
        startNode.cascade(f);
        return r;
    };
    
    //真对单选进行处理
    var nodeAllRadioChange = function(node,bool){
        if(!bool){
            return;
        }
        var treePanel = Ext.getCmp('tree-demo-panel');
        var nodes = getNodes(treePanel);
        if(nodes && nodes.length>0){
            for(var i=0,len=nodes.length;i<len;i++){
                if(nodes[i].id!=node.id){
                    if(nodes[i].getUI().checkbox){
                        nodes[i].getUI().checkbox.checked = false;
                    }
                }
            }
        }
    };
    // 树panel
    var treePanel = new Ext.tree.TreePanel({
        id : 'tree-demo-panel',
        autoScroll : true,
        animate : true,
        border : false,
        root : rootNode,
        loader : treeLoader,
        listeners : {
            'beforeload' : function(node) {
                node.attributes.depth = node.getDepth();
            },
            'click' : function(node, event) {
                                    if(node.getUI().checkbox.checked == true){
                                   node.getUI().checkbox.checked = false;
                              }else{            
                                         node.getUI().checkbox.checked = true;
                          }
                    },
            'checkchange' : function(node, bool) {
                //多选
                //nodeSubCheckChange(node, bool);
                //选择子节点则对应的所有父节点必须选择
                //nodeParCheckChange(node, bool);
                //单选
                nodeAllRadioChange(node,bool);
            }
        }
    });
    
    return {
        // 创建window
        createWindow : function() {
            var win = new Ext.Window({
                id : 'treeWin',
                title : 'tree列表',
                pageX : 100,
                pageY : 100,
                width : 250,
                autoHeight : true,
                closeAction : 'close',
                plain : true,
                buttonAlign : "center",
                resizable : false,
                modal : true,
                items : [treePanel],
                buttons : [{
                    text : '保存',
                    handler : function() {
                                var selectedNode = treePanel.getSelectionModel().getSelectedNode();
       
                 
                   alert(selectedNode.length);//这报错了，请指教！

                    }
                }, {
                    text : '取消',
                    handler : function() {
                        win.close();
                    }
                }]
            });
            win.show();
        }
    }
}();