data() {
  return {
   space: "",
   allresult: []
  };
 },
 methods: {
  getmessage() {
   this.allresult = [];
   axios
    .get(
     "https://gist.githubusercontent.com/xiaolannuoyi/9b0defe4959e71fa97e6096cc4f82ba4/raw/4be939123d488cee7ecefc055fb5ecb2ed8d5c8d/test"
    )
    .then(data => {
     console.log(data);
     let result = data.data;
     for (let i = 0; i < result.length; i++) {
      //原因在于这里的this.Allresult
      this.allresult.push({
       id: result[i].id,
       name: result[i].name,
       age: result[i].age
      });
      
     }
      console.log('此时的this.allresult',this.allresult);
    });
  }
 },
 watch: {
  space() {
   console.log("watch");
   this.getmessage();
  }
 },
 mounted() {
  this.space = "123";
  console.log("mounted");
  this.getmessage();
 }