https://blog.csdn.net/qq_26769677/article/details/79728504
var treeObj = $.fn.zTree.getZTreeObj("permission_tree");
var childNodes = treeObj.transformToArray(treeObj.getNodes());
var pid;
for ( var j = 0; j < childNodes.length; j++) {
alert(childNodes[j].pId);
if (childNodes[j].isHomePage == 1) {
pid = childNodes[j].pId;
}
}
alert(pid);