tp5-登录验证（单一入口）

控制器 Common.php 

<?php
namespace app\admin\controller;
use think\Controller;

class Common extends Controller
{
    public function _initialize()
    {
        if (!session('id') || !session('name')) {
            $this::error("您尚未登录系统！",url('login/login'));
        }
    }   
    
}

控制器 Login.php

<?php
namespace app\admin\controller;
use think\Db;
use think\Controller;
use app\admin\model\Login as LoginModel;

class Login extends Controller
{
    public function login()
    {       
        return view();
    }
    public function index()
    {
         if (request()->isPost()) {
            $admin = new LoginModel();
            $num = $admin->login(input("post."));
            if ($num == 1) {
                $this::error("用户不存在，请检查！");
            }
            if($num == 2){
                $this::success("登录成功~",url('user/index'));
            }
            if ($num == 3) {
                $this::error("密码错误！请检查~");
            }
            return;
        }
        return view("login");

    }
     public function layout()
    {
        session(null);
        $this::success("退出成功！",url('login/login'));
    }
}

model  Login.php

<?php
namespace app\admin\model;
use think\Model;
use think\Db;
class Login extends Model
{
	public function login($data)
	{
		$user = db('user')->where('name',$data['name'])->find();
		if ($user) {
			if ($user['password'] == md5($data['password'])) {
				session('id',$user['id']);
				session('name',$user['name']);
				return 2;
			}else{
				return 3;
			}
		}else{
			return 1;
		}
	}
}

控制器（Login.php 除外）继承 Common 就可以实现单一入口