# 06 AbortController 中断 fetch

AbortController 可以用来终止一个或多个 Web 请求。

## 基础用法

```javascript
// 创建 AbortController 的实例
const controller = new AbortController()
const signal = controller.signal

// 监听 abort 事件，在 controller.abort() 执行后执行回调打印
signal.addEventListener('abort', () => {
  console.log(signal.aborted) // true
})

// 触发中断
controller.abort()
```

## 演示

fetch 接受 `AbortSignal` 作为第二个参数的一部分：

```javascript
const controller = new AbortController()
const signal = controller.signal

fetch('https://slowmo.glitch.me/5000', { signal })
  .then((r) => r.json())
  .then((response) => console.log(response))
  .catch((err) => {
    if (err.name === 'AbortError') {
      console.log('Fetch was aborted')
    } else {
      console.log('Error', err)
    }
  })

// 在 2s 后中断请求，将触发 'AbortError'
setTimeout(() => controller.abort(), 2000)
```

## axios 中使用

```javascript
const controller = new AbortController()

axios
  .get('/foo/bar', {
    signal: controller.signal,
  })
  .then(function (response) {
    //...
  })
// 取消当前请求
controller.abort()
```


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://chanshiyu.gitbook.io/blog/qian-duan/shi-zhan-xi-lie/06abortcontroller-zhong-duan-fetch.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.