thinkphp登录验证

<?php
namespace app\index\controller;

use think\Controller;
use think\Request;

class Login extends Controller
{
    public function index(Request $request)
    {
        if ($request->isPost()) {
            $username = $request->post('username');
            $password = $request->post('password');

            // 假设用户信息存储在数据库中
            $user = Db::name('users')->where('username', $username)->find();

            if ($user && password_verify($password, $user['password'])) {
                // 验证成功，设置 Session
                session('user_id', $user['id']);
                return redirect('/index/index');
            } else {
                return '用户名或密码错误';
            }
        }

        return $this->fetch();
    }

    public function logout()
    {
        // 销毁 Session
        session(null);
        return redirect('/login');
    }
}