node.js - fetch submits post requests across domains, but the background node cannot accept ctx.request.body?

Question

用fetch提交跨域的post请求，但是后台node服务根本找不到提交的数据，没有body的属性
请求代码如下：

  let url='http://127.0.0.1:8080/manager/user/add';
 fetch(url , {  
  method: 'POST',  
 headers: {},
    credentials: 'credentials',
    cache: 'default',
   body: `projectName=dddddd ` 
  // body: insertData,  
}).then((response) => {  
  if (response.ok) {  
      return response.json();  
  }  
}).then((json) => {  
  let userList=JSON.stringify(json);
   dispatch({ type:ADD_USER, userList: userList });  
}).catch((error) => {  
  console.error(error);  
}); 
    }
   后台打印如下： 

Could you please take a look! !

Answer 1

Header content needs to be added, taking json as an example:
headers: { 'Accept': 'application/json', 'Content-Type': 'application/json', }

Answer 2

Node needs to introduce the body-parser middleware module to obtain ajax submission.