有哪位大神回用layuixtree啊，怎么过去选中的节点值，为什么选中节点，子节点的值获取不到啊

tree.render({
elem: '#dept_tree',
data: getData(),
id: 'treeId',
showCheckbox: true, //是否显示复选框
onlyIconControl: true,
checkClick: true,
});
// 获取选中节点的id
function getChecked_list(checkData) {
var treeId = "";
$.each(checkData, function (index, item) {
//console.log(item.id)
if (treeId != "") {
treeId = treeId + "," + item.id;
} else {
treeId = item.id;
}
var i = getChecked_list(item.children);
if (i != "") {
treeId = treeId + "," + i;
}
});
return treeId;
}

获取个鸡子。老子整半天了数组就是空的