使用req.session.xxx时出现 Cannot set property ‘xxxx‘ of undefined

￡神魔★判官ぃ 2022-12-28 05:30 81阅读 0赞

## 问题如下 ##

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQxNzY3OTQ1_size_16_color_FFFFFF_t_70]

#### 查看app.js 代码发现引入的session模块 为灰色没有使用 ####

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQxNzY3OTQ1_size_16_color_FFFFFF_t_70 1]

#### 查看express-session中的[官方文档][Link 1]其中req.session使用案例为： ####

// Use the session middleware
    app.use(session({  secret: 'keyboard cat', cookie: {  maxAge: 60000 }}))
    
    // Access the session as req.session
    app.get('/', function(req, res, next) { 
      if (req.session.views) { 
        req.session.views++
        res.setHeader('Content-Type', 'text/html')
        res.write('<p>views: ' + req.session.views + '</p>')
        res.write('<p>expires in: ' + (req.session.cookie.maxAge / 1000) + 's</p>')
        res.end()
      } else { 
        req.session.views = 1
        res.end('welcome to the session demo. refresh!')
      }
    })

#### 发现没有配置session的中间件 ####

app.use(session({  secret: 'keyboard cat', cookie: {  maxAge: 60000 }}))

##### 固配置中间件 #####

// 配置session的中间件
    app.use(session({  secret: 'secret key' }));

##### 运行结果显示正常： #####

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQxNzY3OTQ1_size_16_color_FFFFFF_t_70 2]

[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQxNzY3OTQ1_size_16_color_FFFFFF_t_70]: /images/20221120/32d79ec980224001ba6c4aee7f6f21c1.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQxNzY3OTQ1_size_16_color_FFFFFF_t_70 1]: https://img-blog.csdnimg.cn/2020121420144125.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQxNzY3OTQ1,size_16,color_FFFFFF,t_70
[Link 1]: https://www.expressjs.com.cn/en/resources/middleware/session.html
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQxNzY3OTQ1_size_16_color_FFFFFF_t_70 2]: https://img-blog.csdnimg.cn/20201214202255525.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQxNzY3OTQ1,size_16,color_FFFFFF,t_70