通过JS获取你当前的网络状况？建议大家学一学-51CTO.COM

前言

大家好，我是林三心，用最通俗易懂的话讲最难的知识点是我的座右铭，基础是进阶的前提是我的初心。

检测网速

想要在Web端检测网速，其实很简单，有一个全局的对象——navigation，我们来看看它的身上都有哪些东西：

图片

属性	描述	类型
downlink	有效带宽估算（单位：兆比特/秒）	number
effectiveType	effectiveType	slow-2g/2g/3g/4g
rtt	当前连接下评估的往返时延	number
saveData	用户代理是否设置了减少数据使用的选项	boolean

useNetwork

我们可以自定义一个hook，用来获取网页当前的网络状态~需要具备以下要素：

1、返回的数据所需的ts类、监听网络变化的enum

2、获取网络状态

3、监听网络变化，并实时更新最新的网络状态

第一步：所需的ts类型

说说NetworkState的各个参数：

since：记录当时检测的时间
oline：记录是否有网络
rtt：记录时延
downlink：记录带宽
saveData：记录用户代理是否设置了减少数据使用
effectiveType：网络连接类型

// hook返回的值
interface NetworkState {
  since?: Date;
  online?: boolean;
  rtt?: number;
  downlink?: number;
  saveData?: boolean;
  effectiveType?: string;
}

// 监听网络变化的事件名enum
enum NetworkEventType {
  ONLINE = 'online',
  OFFLINE = 'offline',
  CHANGE = 'change',
}

第二步：获取网络状态

function getConnection() {
  const nav = navigator as any;
  if (typeof nav !== 'object') return null;
  return nav.connection || nav.mozConnection || nav.webkitConnection;
}

function getConnectionProperty(): NetworkState {
  const c = getConnection();
  if (!c) return {};
  return {
    rtt: c.rtt,
    saveData: c.saveData,
    downlink: c.downlink,
    effectiveType: c.effectiveType,
  };
}

第三步：实时更新网络状态

unction useNetwork(): NetworkState {
  const [state, setState] = useState(() => {
    return {
      since: undefined,
      online: navigator?.onLine,
      ...getConnectionProperty(),
    };
  });

  useEffect(() => {
    const onOnline = () => {
      setState((prevState) => ({
        ...prevState,
        online: true,
        since: new Date(),
      }));
    };

    const onOffline = () => {
      setState((prevState) => ({
        ...prevState,
        online: false,
        since: new Date(),
      }));
    };

    const onConnectionChange = () => {
      setState((prevState) => ({
        ...prevState,
        ...getConnectionProperty(),
      }));
    };

    window.addEventListener(NetworkEventType.ONLINE, onOnline);
    window.addEventListener(NetworkEventType.OFFLINE, onOffline);

    const connection = getConnection();
    connection?.addEventListener(NetworkEventType.CHANGE, onConnectionChange);

    return () => {
      window.removeEventListener(NetworkEventType.ONLINE, onOnline);
      window.removeEventListener(NetworkEventType.OFFLINE, onOffline);
      connection?.removeEventListener(NetworkEventType.CHANGE, onConnectionChange);
    };
  }, []);

  return state;
}

完整代码

import { useEffect, useState } from 'react';

export interface NetworkState {
  since?: Date;
  online?: boolean;
  rtt?: number;
  downlink?: number;
  saveData?: boolean;
  effectiveType?: string;
}

enum NetworkEventType {
  ONLINE = 'online',
  OFFLINE = 'offline',
  CHANGE = 'change',
}

function getConnection() {
  const nav = navigator as any;
  if (typeof nav !== 'object') return null;
  return nav.connection || nav.mozConnection || nav.webkitConnection;
}

function getConnectionProperty(): NetworkState {
  const c = getConnection();
  if (!c) return {};
  return {
    rtt: c.rtt,
    saveData: c.saveData,
    downlink: c.downlink,
    effectiveType: c.effectiveType,
  };
}

function useNetwork(): NetworkState {
  const [state, setState] = useState(() => {
    return {
      since: undefined,
      online: navigator?.onLine,
      ...getConnectionProperty(),
    };
  });

  useEffect(() => {
    const onOnline = () => {
      setState((prevState) => ({
        ...prevState,
        online: true,
        since: new Date(),
      }));
    };

    const onOffline = () => {
      setState((prevState) => ({
        ...prevState,
        online: false,
        since: new Date(),
      }));
    };

    const onConnectionChange = () => {
      setState((prevState) => ({
        ...prevState,
        ...getConnectionProperty(),
      }));
    };

    window.addEventListener(NetworkEventType.ONLINE, onOnline);
    window.addEventListener(NetworkEventType.OFFLINE, onOffline);

    const connection = getConnection();
    connection?.addEventListener(NetworkEventType.CHANGE, onConnectionChange);

    return () => {
      window.removeEventListener(NetworkEventType.ONLINE, onOnline);
      window.removeEventListener(NetworkEventType.OFFLINE, onOffline);
      connection?.removeEventListener(NetworkEventType.CHANGE, onConnectionChange);
    };
  }, []);

  return state;
}

export default useNetwork;