WebSocket connection to ‘ws://localhost:3000/ws‘ failed: Error in connection establishment: net::ERR

出现的错误情况：

vue创建项目打开页面后可以运行正常，就是控制台一直隔几秒报websocket的connection错误

错误如下：

WebSocket connection to 'ws://localhost:3000/ws' failed: Error in connection establishment: net::ERR_CONNECTION_REFUSED

 解决方法：

 在vue.config.js中进行下列的配置

const { defineConfig } = require('@vue/cli-service')
module.exports = defineConfig({
  transpileDependencies: true,
  lintOnSave: false,  //关闭语法检查
  devServer:{
    host: '0.0.0.0',
    port:3000,
    client: {
      webSocketURL: 'ws://0.0.0.0:3000/ws',
    },
    headers: {
      'Access-Control-Allow-Origin': '*',
    }
  }
})