main.js:
import axios from 'axios' //npm install axios -S
import VueAxios from "vue-axios" //npm install axios vue-axios --save
Vue.use(VueAxios,axios)

命令：
npm install axios -S
npm install axios vue-axios --save

函数内使用：
如：

        this.axios  //这里要加this
        .get(
          "https://www.fastmock.site/mock/820259754c7de3b262ea7aa67d2f663a/manage/product2",
          {
            params: {
              name: this.screenKey.name,
              region: this.screenKey.region,
              keyword: this.screenKey.keyword,
              barcode: this.screenKey.barcode,
              classify: this.screenKey.classify,
              allType: this.screenKey.allType,
              allSellType: this.screenKey.allSellType,
            },
          }
        )
        .then((ret) => {
          console.log(ret)
          this.productsData = ret.data.data;//这里注意有几个data
        })
        .catch(function (ret) {
          console.log("error");
          console.log(ret.data);
        })