vue中返回结果是promise的处理方式

<script>
new Promise((resolve, reject) =>{
    setTimeout(() =>{
        //成功的时候调用resolve
        resolve('成功data')
        //失败的时候调用reject
        reject('error message')
    }, 1000)
}).then((data) =>{
    //处理成功后的逻辑
    console.log(data);//这个data 是接收的resolve参数--
}).catch((err) =>{
    console.log(err);
})
</script>　　

p1().then(p2).then(p3)
  .then(function(data) {
    console.log('data: ' + data);
  })
  .catch(function(error) {
    console.log('error: ' + error);
  });
  
function p1() {
  return new Promise(function(resolve, reject) {
    console.log('p1 resolved');
    resolve(123);
  });
}
  
function p2() {
  return new Promise(function(resolve, reject) {
    console.log('p2 rejected');
    reject(456);
  });
}
  
function p3() {
  return new Promise(function(resolve, reject) {
    console.log('p3 resolved');
    resolve(789);
  });
}// 执行结果p1 resolvedp2 rejectederror: 456

function doubleAfter2seconds(num) {
    return new Promise((resolve, reject) => {
        setTimeout(() => {
            resolve(2 * num)
        }, 2000);
    } )
}//写一个async 函数，从而可以使用await 关键字， await 后面放置的就是返回promise对象的一个表达式，所以它后面可以写上 doubleAfter2seconds 函数的调用
async function testResult() {
    let result = await doubleAfter2seconds(30);
    console.log(result);
}

async getUserList(){
            const {data: res} = await this.$http.get('users', {
                params: this.queryInfo
            })
            //console.log(res)
            if (res.meta.status !== 200) return this.$message.error('获取用户列表失败! ')
            this.userlist = res.data.users
            this.total = res.data.total
        }