利用promise封装ajax,axios过程

封装ajax

var url = https://hq.tigerbrokers.com/fundamental/finance_calendar/getType/2017-02-26/2017-06-10;

// 封装一个get请求的方法
function getJSON(url) {
    return new Promise(function(resolve, reject) {
        var XHR = new XMLHttpRequest();
        XHR.open(GET, url, true);
        XHR.send();

        XHR.onreadystatechange = function() {
            if (XHR.readyState == 4) {
                if (XHR.status == 200) {
                    try {
                        var response = JSON.parse(XHR.responseText);
                        resolve(response);
                    } catch (e) {
                        reject(e);
                    }
                } else {
                    reject(new Error(XHR.statusText));
                }
            }
        }
    })
}

getJSON(url).then(resp => console.log(resp));

封装axios

​
function myGet(url, params) {
  return new Promise((resolve, reject) => {
    axios.get(url, params).then(function (response) {
      resolve(response.data)
    })
    .catch(function (err) {
      reject(err)
    })
  })
}

myGet(url,params).then(function(data){console.log(data)}).catch(function(){})
​