genator.js 里 console.log(this)

输出的是这个：

{
"request": {
"method": "POST",
"url": "/?signature=0df9702db39eff72431fbd6d7e2ae5e8d397904b&timestamp=1500341060&nonce=876654093&openid=osgZos0gMAn2VqcUJa8YzbE_GO8s",
"header": {
"user-agent": "Mozilla/4.0",
"accept": "*/*",
"host": "wxfan.ngrok.cc",
"pragma": "no-cache",
"content-length": "276",
"content-type": "text/xml"
}
},
"response": {
"status": 404,
"message": "Not Found",
"header": {}
},
"app": {
"subdomainOffset": 2,
"proxy": false,
"env": "development"
},
"originalUrl": "/?signature=0df9702db39eff72431fbd6d7e2ae5e8d397904b&timestamp=1500341060&nonce=876654093&openid=osgZos0gMAn2VqcUJa8YzbE_GO8s",
"req": "<original node req>",
"res": "<original node res>",
"socket": "<original node socket>"

为什么 this.query是这个？前面的this对象里并没有query这个key

 this.query: { signature: '0df9702db39eff72431fbd6d7e2ae5e8d397904b',
  timestamp: '1500341060',
  nonce: '876654093',
  openid: 'osgZos0gMAn2VqcUJa8YzbE_GO8s' }

2. 这里 this.charset this.length 也是undefined

            console.log('test this charset:',this.charset);
            console.log('test this length:',this.length);
            let data=yield getRawBody(this.req,{
                length:this.length,
                limit:'1mb',
                encoding:this.charset
            })


// 后台输出：
-------------------------------
test this charset: undefined
test this length: undefined
------------------------------