var data = [
    { id: 1, name: "办公管理", pid: 0 },
    { id: 2, name: "请假申请", pid: 1 },
    { id: 3, name: "出差申请", pid: 1 },
    { id: 4, name: "请假记录", pid: 2 },
    { id: 5, name: "系统设置", pid: 0 },
    { id: 6, name: "权限管理", pid: 5 },
    { id: 7, name: "用户角色", pid: 6 },
    { id: 8, name: "菜单设置", pid: 6 },
];
function toTree(data) {
    // 删除 所有 children,以防止多次调用
    data.forEach(function (item) {
        delete item.children;
    });

    // 将数据存储为 以 id 为 KEY 的 map 索引数据列
    var map = {};
    data.forEach(function (item) {
        map[item.id] = item;
    });
    //        console.log(map);
    var val = [];
    data.forEach(function (item) {
        // 以当前遍历项，的pid,去map对象中找到索引的id
        var parent = map[item.pid];
        // 好绕啊，如果找到索引，那么说明此项不在顶级当中,那么需要把此项添加到，他对应的父级中
        if (parent) {
            (parent.children || (parent.children = [])).push(item);
        } else {
            //如果没有在map中找到对应的索引ID,那么直接把 当前的item添加到 val结果集中，作为顶级
            val.push(item);
        }
    });
    return val;
}
console.time()
console.log(toTree(data))
console.timeEnd();

console.time()
var nodes = [
{
    "id": "12",
    "parentId": "0",
    "text": "Man",
    "level": "1",
},
{
    "id": "13",
    "parentId": "12",
    "text": "Man",
    "level": "1",
},
{
    "id": "14",
    "parentId": "13",
    "text": "Man",
    "level": "1",
},
{
    "id": "15",
    "parentId": "15",
    "text": "Man",
    "level": "1",
},
{
    "id": "16",
    "parentId": "12",
    "text": "Man",
    "level": "1",
},];
var map = {}, node, roots = [];
for (var i = 0; i < nodes.length; i += 1) {
node = nodes[i];
node.children = [];
map[node.id] = i; // use map to look-up the parents
if (node.parentId !== "0") {
    nodes[map[node.parentId]].children.push(node);
} else {
    roots.push(node);
}
}
console.timeEnd();
console.log(roots); // <-- there's your tree

$(window).trigger('resize');

if (Event.prototype.initEvent) {
    const evt = window.document.createEvent('UIEvents');
    evt.initUIEvent('resize', true, false, window, 0);
    window.dispatchEvent(evt);
else {
    window.dispatchEvent(new Event('resize'));
}

import _ from 'lodash';

// Avoid costly calculations while the window size is in flux.
jQuery(window).on('resize', _.debounce(calculateLayout, 150));

handleSubmit(e) {
        e.preventDefault();

        const { name, password, department, gender } = this.state;
        fetch('http://localhost:8080/api/user', {
            mode: "cors",  
            method: 'POST',
            // 使用fetch提交的json数据需要使用JSON.stringify转换为字符串
            body: JSON.stringify({
                name,
                password,
                department,
                gender
            }),
            headers: {
                "Content-Type": "application/x-www-form-urlencoded",
            }
        })
            .then((res) => res.json())
            .then((res) => {
                // 当添加成功时，返回的json对象中应包含一个有效的id字段
                // 所以可以使用res.id来判断添加是否成功
                if (res.id) {
                    alert('添加用户成功');
                    this.setState({
                        name: '',
                        password: 0,
                        gender: ''
                    });
                } else {
                    alert('添加失败');
                }
            })
            .catch((err) => console.error(err));
    }