1、通过AbortController

这是官方标准手段，真正意义的阻止请求（不支持ie）

后端接口设置的两秒返回数据

function myFetch() {const controller = new AbortController();const signal = controller.signal;fetch('http://localhost:3000/aaa/bbb', {method: 'post',signal,headers: {'Content-Type': 'application/json'}}).then(res => res.json()).then(res => {console.log(res);return res;}).catch(e => {console.log(e);})// setTimeout(()=> {//     controller.abort();// }, 1000)
}

默认结果：

解开定时器后：

2、模拟中断

通过promise，成功用resolve返回，失败用reject返回（浏览器上，请求依然会发出，并得到响应）
第一种方法：

function getData() {return new Promise((resolve, reject) => {myFetch().then(res => {resolve(res);});setTimeout(() => {reject({code: '500',msg: '请求失败'})}, 1000);})
}async function gotData() {try {const data = await getData();console.log(data);} catch (error) {console.log(error);}
}
gotData();

运行结果：

第二种方法：

function getData() {let myReject = null;let myPromise = new Promise((resolve, reject) => {myReject = reject;myFetch().then(res => {resolve(res);});});myPromise.abort = () => myReject({code: '500',msg: '请求失败'});return myPromise;
}async function gotData() {const result = getData();result.then(res => {console.log(res);}).catch(e => {console.log(e);})setTimeout(() => {result.abort();}, 1000);
}
gotData();