_requestData(callback,_cityDt){

    const switchIp = "http://192.168.43.103/api/proxy";

    let formData = new FormData();

        formData.append("type","get");

        formData.append("open_redis",1);

        formData.append("redis_time",0);

    fetch(switchIp, {

            method:"POST",

               body:formData

           }).then(

            (response)=>{

                if(response.ok){

                    return response.json()

                }else{

                    return Promise.reject({

                        status: response.status,

                        statusText: response.statusText

                    })

                }

            })

            .then((responseJsonData)=> {

                callback && callback(responseJsonData);

            }).catch((error)=> {

                console.log("getWatchHistory error " + error);

            });

    }

let _cityDt = “beijing”;  //需要传递的参数，不需要不传

this._requestData((data)=>{

    const res = JSON.parse(data);

    //执行数据的处理相关操作

    ........

    //执行初始化数据的操作

    this._initData();

},_cityDt)

_requestData(callback,_id){

     const url = `http://192.114.90.121/data/api/trend?evt=${_id}`;

     fetch(url, {}).then(

            (response)=>{

            if(response.ok){

                return response.json()

            }else{

                return Promise.reject({

                    status: response.status,

                    statusText: response.statusText

            })

         }

    }).then((responseJsonData)=> {

                callback && callback(responseJsonData);

            }).catch((error)=> {

                console.log("getWatchHistory error " + error);

            });

    }

let _id = "123";

this._requestData((data)=>{

　 //执行数据渲染的函数

    this._play(data)

},_id)