Ext TreePnael选中节点及获取选中的节点

function checkNode(node) {
    //Ext.Msg.alert('提示',node.getUI().isChecked() );
    uncheckParentNode(node);
    checkChildNodes(node, node.getUI().isChecked());
}
function checkChildNodes(node, checked) {
    var nodeArray = node.childNodes;
    for (var i = 0; i < nodeArray.length; i++) {
        nodeArray[i].getUI().checkbox.checked = checked;
        if (nodeArray[i].hasChildNodes())
            checkChildNodes(nodeArray[i], checked);
    }
}
function uncheckParentNode(node) {
    // todo unselected all children
    if (node.parentNode != undefined) {
        var checked = getcheckcount(node) != ""; //递归中返回不了0，不知为什么
        if (node.parentNode.getUI().checkbox != undefined) {
            node.parentNode.getUI().checkbox.checked = checked;
        }
        uncheckParentNode(node.parentNode);
    }
}
function getcheckcount(node) {
    var count = 0;
    var nodeArray = node.parentNode.childNodes;
    for (var i = 0; i < nodeArray.length; i++) {
        if (nodeArray[i].getUI().isChecked()) {
            count++;
        }
    }
    return count;
}
//获取选中节点
function getCheckedNode(node) {
    var result = "";
    //判断根节点是否选中
    if (node.getUI().checkbox.checked) {
        if (node.id != "root") {
            result += node.id + ",";
        }
    }
    var treeNodes = node.childNodes;
    //遍历根节点下的所有子节点
    for (var i = 0; i < treeNodes.length; i++) {
        if (treeNodes[i].getUI().checkbox.checked) {
            result += treeNodes[i].id + ",";
            if (treeNodes[i].childNodes.length > 0) {
                var tmp = getCheckedNode(treeNodes[i]);
                result = tmp;
            }
        }
    }
    return result;
}