HarmonyOS http 请求 post 参数问题

let httpRequest = http.createHttp();  
httpRequest.request(APIConst.Home_InfoFlow, {  
  method: http.RequestMethod.POST,  
  header: {  
    'Content-Type': 'application/x-www-form-urlencoded'  
  },  
  extraData: {  
    id: "123",  
    name: "4567",  
    value: "哈啊大声道",  
    pageNo: 1,  
    pageSize: 20,  
    flowClassId: 3  
  },  
  usingProxy: {  
    host: "http://196.3.2.233",  
    port: 8888,  
  } as http.HttpProxy  
}, (err: BusinessError, data: http.HttpResponse) => {  
  console.log("123", JSON.stringify(data))  
  console.log("543", err)  
})

{"id":"123","name":"4567","value":"哈啊大声道","pageNo":1,"pageSize":20,"flowClassId":3} 

id=123&name=4567&value=哈啊大声道&pageNo=1&pageSize=20&flowClassId=3