小程序下载实现

   这是小程序结构图和实现效果

1.config->httpconfig.js 这是个工具js

function sendPost(cb, data, url) {
  wx.request({
    url: url,
    method: 'POST',
    dataType: "json",
    header: {
      "Content-Type": "application/x-www-form-urlencoded"
    },
    data: data,
    success: function (res) {      
      cb(res.data)
    },
    fail: function (res) {

    }
  });
}
function sendGet(success, data, url) {
  wx.request({
    url: url,
    method: 'GET',
    header: {
      "Content-Type": "application/x-www-form-urlencoded"
    },
    data: data,
    success: function (res) {
      success(res.data);
    },
    fail: function(r