Vue3+TS教程_vue3 ts

Vue3

组合式API

1.钩子函数steup

1. 函数的普通用法

<script>
export default {
    setup() {return {}}
}
</script>
<template></template>

1. 简写使用setup

<script setup></script><template></template>

2.响应式API

1. ref函数

<script setup>
import { ref } from 'vue'
const state = ref(0)
function increment() {
    state.value++
}
</script>
<template>
    <button @click="increment">{{ state }}</button>
</template>

1. reactive函数

<script setup>
import { reactive } from 'vue'
const state = reactive({ count: 0 })
function increment() {
    state.count++
}
</script>
<template>
    <button @click="increment">{{ state.count }}</button>
</template>

3.计算属性API

1. 单向响应

<script setup>
import { computed,reactive } from 'vue'
const Person=reactive({X:'张',M:'三'})
Person.XM=computed(()=>{return Person.X+'-'+Person.M})
</script>
<template>
姓:<input v-model="Person.X">
<br>
名:<input v-model="Person.M">
<br>
单向响应:<input v-model="Person.XM">
</template>

1. 双向响应

<script setup>
import { computed,reactive } from 'vue'
const Person=reactive({X:'张',M:'三'})
Person.AXM=computed({
    get(){
        return Person.X+'-'+Person.M
    },
    set(value){
        const arr=value.split('-')
        Person.X=arr[0]
        Person.M=arr[1]
    }
})
</script>
<template>
    姓:<input v-model="Person.X">
    <br>
    名:<input v-model="Person.M">
    <br>
    双向响应:<input v-model="Person.AXM">
</template>

4.监听属性API

1. 监听整个对象

<!--  // 监听整个对象,由于是浅拷贝，他们新旧指向的是通一个对象 -->
<script setup>
import {reactive,watch} from 'vue'
const Person=reactive({
    name:'张三',
    age:18, 
    job:{salary:20}
})
watch(Person,(newVal,oldVal)=>{
    console.log('用户信息发生了变化',newVal,oldVal);
})
</script>
<template>
<h2>年龄：{{Person.age}}</h2>
<button @click="Person.age++">+1</button>
</template>

1. 监听对象中单个属性

<!-- 监听对象中单个属性,监听单个属性可以检测到新旧值 -->
<script setup>
import { strict } from "assert";
import { reactive, watch } from "vue";
const Person = reactive({
  name: "张三",
  age: 18,
  job: { salary: 20 },
});
watch(
  () => Person.age,
  (newVal, oldVal) => {
    console.log("用户年龄发生了变化", newVal, oldVal);
  }
);
</script>
<template>
  <h2>年龄：{{ Person.age }}</h2>
  <button @click="Person.age++">+1</button>
</template>        

1. 监听多个对象

<script setup>
import { reactive, watch } from "vue";
const Person = reactive({ name: "张三", age: 18, job: { salary: 20 } });
watch([() => Person.name, () => Person.age], (newValue, oldValue) => {
  console.log("person.name或者person.age的值变化了", newValue, oldValue);
});
</script>
<template>
  <h2>姓名：{{ Person.name }}</h2>
  <button @click="Person.name += '~'">修改</button>
  <h2>年龄：{{ Person.age }}</h2>
  <button @click="Person.age++">+1</button>
</template >

1. 监听对象中对象(深度监听)

<!-- 监听对象中对象,必须开启深度监听,一般情况不监听对象 -->
<script setup>
import { reactive, watch } from "vue";
const Person = reactive({ name: "张三", age: 18, job: { salary: 20 } });
watch(
  () => Person.job,
  (newValue, oldValue) => {
    console.log("person.job的值变化了", newValue, oldValue);
  },
  { deep: true }
);
</script>
<template>
  <h2>薪资：{{ Person.job.salary }}K</h2>
  <button @click="Person.job.salary++">+1</button>
</template>

5.高级监听API

1. 基本使用(默认执行一次)

<!-- watchEffect所指定的回调中用到的数据只要发生变化，则直接重新执行回调。 -->
<script setup>
import { reactive, watchEffect } from "vue";
const Person = reactive({ name: "张三" });
watchEffect(() => {
  Person.name;
  console.log("姓名发送了变化:" + Person.name,);
});
</script>
<template>
  <h2>姓名：{{ Person.name }}</h2>
  <button @click="Person.name += '~'">修改</button>
</template>

1. 监听御前处理oninvalidate参数

<script setup lang="ts">
import { reactive, watchEffect } from "vue";
const Person = reactive({ name: "张三" });
watchEffect((oninvalidate) => {
  oninvalidate(() => {
    console.log("before");
  });
  Person.name;
  console.log("姓名发送了变化");
});
</script>
<template>
  <h2>姓名：{{ Person.name }}</h2>
  <button @click="Person.name += '~'">修改</button>
</template>

1. 停止监听

<script setup lang="ts">
import { reactive, watchEffect } from "vue";
const Person = reactive({ name: "张三" });
const stop = watchEffect((oninvalidate) => {
  oninvalidate(() => {
    console.log("before");
  });
  Person.name;
  console.log("姓名发送了变化");
});
</script>
<template>
  <h2>姓名：{{ Person.name }}</h2>
  <button @click="Person.name += '~'">修改</button
  ><button @click="stop">停止</button>
</template>

6.响应式对象解构API

1. toRef函数

<script setup>
import { reactive, toRef } from "vue";
const person = reactive({ A: 1, B: 2 });
const A = toRef(person, "A");
</script><template>
  <h2>姓名：{{ A }}</h2>
  <button @click="person.A += '~'">修改</button>
</template>

1. toRefs

<script setup lang="ts">
import { reactive, toRefs } from "vue";
const person = reactive({ A: 1, B: 2 });
const { A, B } = toRefs(person);
</script>
<template>
  <h2>姓名：{{ A }}</h2>
  <button @click="A += 1">修改</button>
</template>

7.生命周期API

<script setup>
import {
  onBeforeMount,
  onMounted,
  onBeforeUpdate,
  onUpdated,
  onBeforeUnmount,
  onUnmounted,
  ref,
} from "vue";
onBeforeMount(() => {
  console.log("---挂载之前---");
});
onMounted(() => {
  console.log("---挂载---");
});
onBeforeUpdate(() => {
  console.log("---更新之前---");
});
onUpdated(() => {
  console.log("---更新---");
});
onBeforeUnmount(() => {
  console.log("---卸载之前---");
});
onUnmounted(() => {
  console.log("---卸载---");
});
</script>

8.ref获取dom

<template>
  <div><div ref="box">我是div</div></div>
</template><script>
import { ref, onMounted } from "vue";
export default {
  setup() {
    let box = ref(null);
    //本质是reactive({value:null})
    //需要在生命周期获取
    onMounted(() => {
      // 当界面挂载出来后就会自动执行
      console.log(box.value);
    });
    //接受的是null,原因是setup执行时机比mounted早,dom还没形成
    console.log(box.value);
 
    return { box };
  },
};
</script>

9.Hooks

(1)官方hooks

1. useAttrs()

<!-- 父组件 -->
<template><Acom a="456" title="789" /></template>
 
<!-- 子组件 -->
<!-- 获取父组件传过来的全部参数 -->
<script setup lang="ts">
import { useAttrs } from "vue";
let attr = useAttrs();
console.log(attr);
</script>

(2)自定hooks

1. 自定义hooks转换图片

import { onMounted } from "vue";
type Options = {
  el: string;
};
export default function (options: Options): Promise<{ baseUrl: string }> {
  return new Promise((resolve) => {
    onMounted(() => {
      const img: HTMLImageElement = document.querySelector(
        options.el
      ) as HTMLImageElement;
      img.onload = () => {
        resolve({ baseUrl: base64(img) });
      };
    });
    const base64 = (el: HTMLImageElement) => {
      const canvas = document.createElement("canvas");
      const ctx = canvas.getContext("2d");
      canvas.width = el.widthcanvas.height = el.heightctx?.drawImage(
        el,
        0,
        0,
        canvas.width,
        canvas.height
      );
      return canvas.toDataURL("image/jpg");
    };
  });
}

1. 使用hooks

<script setup lang="ts">
import BASE64 from './hooks'
BASE64({ el: '#img' }).then(resolve => {console.log(resolve.baseUrl)
})
</script>

(3)第三方hooks

1. 安装依赖yarn add @vueuse/core
2. 简单使用

<script setup lang="ts">
import { ref } from "vue";
import { useDraggable } from "@vueuse/core";
const el = ref<HTMLElement | null>(null); // `style` will be a helper computed for `left: ?px; top: ?px;`
const { x, y, style } = useDraggable(el, { initialValue: { x: 40, y: 40 } });
</script>
<template>
  <div ref="el" :style="style" style="position: fixed">
    Drag me! I am at {{ x }}, {{ y }}
  </div>
</template>

组件间通讯

1.props父传子

1. 父组件

<script setup >
import HelloWorld from './components/HelloWorld.vue'
</script>
<template>
    <HelloWorld msg="1"/>
</template>

1. 子组件

<script setup lange="ts">
// const props=defineProps(['msg'])
//const props=defineProps({msg:String})
const props=withDefaults(defineProps<{msg: string}>(), {
msg: ''
});
console.log(props.msg)
</script>

2.emit子传父

1. 父组件

<script setup >
import HelloWorld from './components/HelloWorld.vue'
const getuser=(a)=>{
    console.log(a)
}
</script>
<template>
    <HelloWorld @getuser="getuser"/>
</template>

1. 子组件

<script setup lang="ts">
const emit = defineEmits(['getuser'])
function buttonClick() {
    emit('getuser',1)
}
</script>
<template>
    <button @click="buttonClick">传输</button>
</template>

1. 自定义事件事件校检

<script setup>
const emit = defineEmits({
    // 没有校验click: null,
    // 校验 submit 事件
    submit: ({ email, password }) => {
        if (email && password) {
            return true
        } else {
            console.warn('Invalid submit event payload!')
            return false
        }
    }
})
function submitForm(email, password) {
    emit('submit', { email, password })
}
</script>

3.插槽通讯

(1)匿名插槽

1. 子组件

<template>
    <!-- slot插槽占位 -->
    <slot></slot>
</template>

1. 父组件

<script setup lang="ts">
import HelloWorld from "./components/HelloWorld.vue";
</script>
<template>
    <HelloWorld>插槽传递</HelloWorld>
</template>

(2)具名插槽

1. 父组件

<script setup lang="ts">
import HelloWorld from "./components/HelloWorld.vue";
</script>
<template>
    <HelloWorld>
    <!-- v-slot:简写# -->
    <template v-slot:btn>
        <button>具名插槽</button>
    </template>
    </HelloWorld>
</template>

1. 子组件

<template>
    <!-- slot插槽占位 -->
    <slot name="btn"></slot>
</template>

(3)作用域插槽

1. 理解：数据在子组件的自身，但根据数据生成的结构需要父组件决定。
2. 父组件

<script setup lang="ts">
import HelloWorld from "./components/HelloWorld.vue";
const person = [
  { name: "小明", age: 18 },
  { name: "小红", age: 20 },
];
</script>
<template>
  <!-- 父组件将信息传递给子组件 -->
  <HelloWorld :person="person">
    <!-- 子组件接收父组件的插槽中传的值 -->
    <template #tab="scope">
      <tr v-for="(item, index) in scope.person" :key="index">
        <th>{{ item.name }}</th>
        <th>{{ item.age }}</th>
        <th><button>编辑</button></th>
      </tr>
    </template>
  </HelloWorld>
</template>

1. 子组件

<script setup lang="ts">
const props = defineProps<{ person: { name: string, age: number }[] }>()
</script>
<template>
    <table border="1">
        <tr>
            <th>姓名 </th>
            <th>年龄</th>
            <th>操作 </th>
        </tr>
        <!--作用域插槽命名 -->
        <!-- // 向作用插槽中传值 -->
        <slot name="tab" :person="props.person">
        </slot>
    </table>
</template>

4.依赖注入

1. 父组件(祖先组件)

<!-- 依赖注入传的参可以在子组件中改变 -->
<template>
  <div class="App"><button>我是App</button><A></A></div>
</template>
<script setup lang="ts">
import { provide, ref } from 'vue'
import A from './components/Acom.vue'
let flag = ref<number>(1)
provide('flag', flag)
</script>

1. 子组件(后代组件)

<template>
  <div>我是B<div>{{ flag }}</div><button @click="flag++">+1</button></div>
</template>
<script setup lang="ts">
import { inject, ref } from 'vue'
//  注入值，默认值(让其可以进行类型推断)
const flag = inject('flag', ref(1))
</script>

5.兄弟传参(不推荐)

(1)父组件当成一个桥梁

(2)发布订阅模式

1. Bus传递

type BusClass = {
  emit: (name: string) => void,
  on: (name: string, callback: Function) => void
}
type PramsKey = string | number | symbol
type List = {
  [key: PramsKey]: Array<Function>
}
class Bus implements BusClass {
  list: Listconstructor = () => {
    this.list = {}
  }
  emit(name: string, ...args: Array<any>) {
    const evnentName: Array<Function> = this.list[name]
    evnentName.forEach(fn => {
      fn.apply(this, args)
    })
  }
  on(name: string, callback: Function) {
    const fn: Array<Function> = this.list[name] || []
    fn.push(callback) 
    this.list[name] = fn
  }
}
export default new Bus()

1. A组件传递数值

<script setup lang="ts">
import { ref } from 'vue'
import Bus from '../utils/Bus'
const flag = ref(1)
const Pass = () => {
  Bus.emit('pass', flag)
}
</script>
<template>
  <div>我是A<div>{{ flag }}</div><button @click="Pass">Pass</button></div>
</template>
<style scoped lang="less"></style>

1. B组件接收数值

<script setup lang="ts">
import Bus from '../utils/Bus'
import { ref, type Ref } from 'vue'const flag = ref(0)
Bus.on('pass', (Flag: Ref<number>) => {
  console.log(Flag)
  flag.value = Flag.value
})
</script>
<template>
  <div>我是B <div> {{ flag }}</div><button @click="flag++">+</button> </div>
  <style scoped lang="less"> </style>
</template>

(3)第三方库mitt

1. 安装yarn add mitt
2. 全局挂载mit

<script setup lang="ts">
import { createApp } from 'vue'
import { createPinia } from 'pinia'
import App from './App.vue'
import './assets/main.css'
import mitt from 'mitt'
const Mit = mitt()
const app = createApp(App)// 类型声明
declare module 'vue' {
  export interface ComponentCustomProperties { $Bus: typeof Mit }
}
app.use(createPinia())
app.config.globalProperties.$Bus = Mit
app.mount('#app')
</script>
<template>
  <div>我是B <div> {{ flag }}</div><button @click="flag++">+</button> </div>
  <style scoped lang="less"> </style>
</template>

1. A组件传递数值

<script setup lang="ts">
import { getCurrentInstance, ref } from 'vue'
const instance = getCurrentInstance()
const flag = ref(1)
const Pass = () => {
  instance?.proxy?.$Bus.emit('pass', flag)
}
</script>
<template>
  <div>我是A
    <div> {{ flag }}</div>
    <button @click="Pass">Pass</button>
  </div>
  <style scoped lang="less"> </style>
</template>

1. B组件接收数值

<script setup lang="ts">
import { getCurrentInstance, ref, type Ref } from 'vue'const instance = getCurrentInstance()
const flag = ref(0)
instance?.proxy?.$Bus.on('pass', Flag => {
  flag.value = (Flag as Ref<number>).value
})
</script>
<template>
  <div>我是B<div>{{ flag }}</div><button @click="flag++">+</button></div>
</template>
<style scoped lang="less"></style>

1. *监听事件

<script setup lang="ts">
import { getCurrentInstance, ref, type Ref } from 'vue'
const instance = getCurrentInstance()
const flag = ref(0)
/*** type:事件名称* Flag:传递参数*/
instance?.proxy?.$Bus.on('*', (type, Flag) => {flag.value = (Flag as Ref<number>).value
})
</script>

1. 取消监听事件

<script setup lang="ts">
import { getCurrentInstance, ref, type Ref } from 'vue'const instance = getCurrentInstance()
const flag = ref(0)
instance?.proxy?.$Bus.off('pass', Flag => {flag.value = (Flag as Ref<number>).value
})
</script>

1. 取消全部监听事件

<script setup lang="ts">
import { getCurrentInstance, ref, } from 'vue'
const instance = getCurrentInstance()instance?.proxy?.$Bus.all.clear()
</script>

Typescript的支持

1.全局接口的抽取

1. src下定义types文件夹命名xx.d.ts
2. 建立Person接口person.d.ts

interface personInterface{
    name:string,
    age:number
}

1. 组件中直接使用

<script setup lang="ts">
const props=defineProps<{
    person:personInterface[]
}>()
</script>

1. 如果不是在src下或src文件下的xx.d.ts文件则需要在tsconfig.json中配置

{
  {
    ...
  },
  "include": [
    "src/**/*.ts",
    "src/**/*.d.ts",
    "src/**/*.tsx",
    "src/**/*.vue"
  ], //配置全局目录"references": [{ "path": "./tsconfig.node.json" }]
}

2.类型增强

1. 使用环境：全局定义的数据，函数在vue组件中直接访问报错
2. index.html中定义数据

<!DOCTYPE html>
<html lang="en">
<head>...</head>
<script>
    const  global=1
</script>
<body>...</body>
</html>

1. 定义类型增强

// common.d.ts
declare const global:string;

1. 组件中直接读取

<script setup lang="ts">
console.log(global)
</script>

3.第三方库类型声明

1. 安装一个库
2. 安装库的ts类型声明@types/xxxx

4.props组件通讯TS

1. 父组件

<script setup lang="ts">
import HelloWorld from './components/HelloWorld.vue'
</script>
<template>
<HelloWorld msg="1"/>
</template>

1. 子组件

<script setup lang="ts">
interface msgIterface{
    msg:string
}
const props = withDefaults(defineProps<msgIterface>(),{msg:'默认值'})
console.log(props.msg)
</script>

5.emit组件通讯TS

1. 父组件

<script setup lang="ts">
import HelloWorld from './components/HelloWorld.vue'
const getuser=(a:number)=>{
    console.log(a)
}
</script>
<template>
<HelloWorld @getuser="getuser"/>
</template>
<style scoped>
</style>

1. 子组件

<script setup lang="ts">
const emit = defineEmits<{(e: 'getuser', id: number): void}>()
// (e: 事件名, 键名：类型): void
function buttonClick() {
emit('getuser',1)
}
</script>
<template>
<button @click="buttonClick">传输</button>
</template>
<style scoped></style>

6.依赖注入类型推断

1. 父组件(祖先组件)

<template>
<div class="App"><button>我是App</button><A></A></div>
</template>
<script setup lang="ts">
import { provide, ref } from 'vue'
import A from './components/Acom.vue'
let flag = ref<number>(1)
provide('flag', flag)
</script>

1. 子组件(后代组件)

<template>
<div>我是B
<div>{{ flag }}</div>
<button @click="flag++">+1</button>
</div>
</template>
<script setup lang="ts">
import { inject, ref , type Ref} from 'vue'
//  注入值，默认值(让其可以进行类型推断)
const flag<Ref<number>> = inject('flag', ref(1))
</script>

7.定义全局函数和全局函数的类型支持

import { createApp } from 'vue'
...
const app = createApp(App)
type Fileter = {
    format: <T>(str: T) => string
}
declare module '@vue/runtime-core' 
{
    export interface ComponentCustomProperties {$filters: Fileter$env: string}
}
// 全局函数
app.config.globalProperties.$filters = {
    format<T>(str: T): string 
    { return `真${str}`}
}
// 全局变量
app.config.globalProperties.$env = '全局变量'
...

脚手架Vite

1.基本使用

1. 创建vue3的项目yarn create vite || npm init vite@latest
2. 安装插件Volar

2.配置项目路径

1. tsconfig.json中添加

// 让ts可以识别这个路径
{
    "compilerOptions": {
        ...
        "baseUrl": "./",
        "paths": {
            "@/*":["src/*"]
        }
    },
    ...
}

1. vite.config.ts中添加

 
// https://vitejs.dev/config/
export default defineConfig({
    plugins: [vue()],
    resolve:{
        alias:{"@":join(__dirname,'src')}
    }
})

3.eslint和prettierrc的配置

1. .prettierrc.json

{
"arrowParens": "always",
"bracketSameLine": true,
"bracketSpacing": true,
"embeddedLanguageFormatting": "auto",
"htmlWhitespaceSensitivity": "css",
"insertPragma": false,
"jsxSingleQuote": false,
"printWidth": 120,
"proseWrap": "never",
"quoteProps": "as-needed",
"requirePragma": false,
"semi": false,
"singleQuote": true,
"tabWidth": 2,
"trailingComma": "all",
"useTabs": false,
"vueIndentScriptAndStyle": false,
"singleAttributePerLine": false
}

1. .eslintrc.cjs

/* eslint-env node */
require('@rushstack/eslint-patch/modern-module-resolution')
module.exports = {
    root: true,
    extends: ['plugin:vue/vue3-essential',
    'eslint:recommended',
    '@vue/eslint-config-typescript',
    '@vue/eslint-config-prettier'],
    rules: {
        'vue/multi-word-component-names': 'off', // 关闭命名semi: 0 // 结尾无分号
    },
    parserOptions: {ecmaVersion: 'latest'}
}

4.vite环境变量的配置

1. vite的环境在import中

<script setup lang="ts">
console.log(import.meta.env)
</script>

1. 创建.env.development .env.production
2. package.json中配置运行生产环境,会自动注入

{..."scripts": {"dev": "vite --mode development",...},}

1. vite.config.ts中读取环境变量

import { fileURLToPath, URL } from 'node:url'
import { defineConfig, loadEnv } from 'vite'
import unocss from 'unocss/vite'
import vue from '@vitejs/plugin-vue'
import { presetIcons, presetAttributify, presetUno } from 'unocss'// https://vitejs.dev/config/
export default ({ mode }: any) => {
    // 读取环境变量
    console.log(loadEnv(mode, process.cwd()))
    return defineConfig({
    plugins: [vue()],
    resolve: {
    alias: {
    '@': fileURLToPath(new URL('./src', import.meta.url))
        }
    }
    })
}

1. 找不到模块“./App.vue”或其相应的类型声明

declare module '*.vue' 
 
{
    import type { DefineComponent } from 'vue'
    //eslint-disable-next-line @typescript-eslint/no-explicit-any,@typescript-eslint/ban-    typesconst 
    component: DefineComponent<{}, {}, any>
    export default component
}

1. 类型“ImportMeta”上不存在属性“env”

// tsconfig.json
{
    ...
    "compilerOptions": {
        ...
        "types": [ "vite/client" ],
    },
    ...
}

指令的重构

1.v-model指令

(1)v-model实现组件间数据双向绑定

1. 父组件

<script setup lang="ts">
    import HelloWorld from "./components/HelloWorld.vue";
    import { ref } from "vue";
    const num=ref(1)
</script>
<template>
    <HelloWorld v-model="num"/>
</template>

1. 子组件

<script setup lang="ts">
import { computed } from 'vue';
const props=defineProps<{modelValue:number}>()
const emit = defineEmits<{(e: 'update:modelValue', id: number): void}>()
// 计算属性实现修改数据的同步
const value=computed({
    get(){
        return +props.modelValue
    },
    set(value){
        emit('update:modelValue',+value)
    }
})
</script>
<template>
<input type="text" v-model="value">
</template>

1. v-model的原理

<template>
<!-- <HelloWorld v-model="num"/> -->
<HelloWorld :modelValue="num" @update:modelValue="num = $event"/>
</template>

(2)v-model传递特定的名称

1. 父组件

<script setup lang="ts">
import { ref } from "vue";
import HelloWorld from "./components/HelloWorld.vue";
const num=ref(1)
</script>
<template>
<!-- <HelloWorld :num="num @update:="num = $event""/> -->
<HelloWorld v-model:num="num"/>
</template>

1. 子组件

<script setup lang="ts">
import { computed } from 'vue';
const props=defineProps<{num:number}>()
const emit = defineEmits<{(e: 'update:num', id: number): void}>()
const value=computed({
    get(){return +props.num},
    set(value){emit('update:num',+value)}
})
</script>
<template>
<input type="text"  v-model="value">
</template>

2.自定义指令

(1)自定义指令的简单使用

1. 全局自定义指令

// mian.ts
import { createApp } from 'vue'
import './style.css'
import App from './App.vue'
const app=createApp(App)
app.directive('focus',{
    mounted(el){el.focus()}
})
app.mount('#app')

1. 使用自定义指令

<template>
    <input type="text"  v-model="value" v-focus>
</template>

1. 局部自定义指令

<script setup>
// 在模板中启用 v-focus
const vFocus = {mounted: (el) => el.focus()
}
</script>
<template>
    <input v-focus />
</template>

(2)自定义指令详解

1. 自定义指令的生命周期

<script setup lang="ts">
import type { Directive, DirectiveBinding } from 'vue'
type Dir = { background: string }
const vMove: Directive = {
    created() {}, //元素初始化的时候
    beforeMount() {}, //指令绑定到元素后调用 只调用一次
    mounted(el: HTMLElement, dir: DirectiveBinding<Dir>) {
        console.log(dir.value.background)
        el.style.background = dir.value.background
    },//元素插入父级dom调用
    beforeUpdate() {},//元素被更新之前调用
    updated() {}, //元素被更新时调用
    beforeUnmount() {}, //在元素被移除前调用
    unmounted() {} //指令被移除后调用 只调用一次
}
</script>
<template>
<!-- 自定义指令，参数，修饰符 -->
<div v-move:a.x="{ background: 'red' }">自定义指令</div>
</template>
<style scoped lang="less"></style>

1. 生命周期的简写

<script setup lang="ts">
import type { Directive, DirectiveBinding } from 'vue'
type Dir = { background: string }
const vMove: Directive = (el: HTMLElement, dir: DirectiveBinding<Dir>) => {
    el.style.background = dir.value.background
}
</script>
<template>
<!-- 自定义指令，参数，修饰符 -->
<div v-move:a.x="{ background: 'red' }">自定义指令</div>
</template>
<style scoped lang="less"></style>

1. 自定义拖拽指令

<script setup lang="ts">
import type { Directive } from 'vue'
const vMove: Directive = (el: HTMLElement) => {
    const move = (e: MouseEvent) => {
        console.log(e)
        el.style.left = e.clientX + 'px'
        el.style.top = e.clientY + 'px'
    }
    // 鼠标按下
    el.addEventListener('mousedown', () => {
        // 鼠标按下拖拽
        document.addEventListener('mousemove', move)
        // 鼠标松开
        document.addEventListener('mouseup', () => {
            // 清除事件
            document.removeEventListener('mousemove', move)
        })
    })
}
</script>
<template>
<!-- 自定义指令，参数，修饰符 -->
<div v-move style="background-color: red;width: 200px;height: 200px;position: fixed;left: 50%;top: 50%;transform: translate(-50%, -50%);">
<div style="background-color: black; width: 200px; color: white">自定义指令</div>
</div>
</template>

响应式原理

1.了解Proxy

1. Proxy代理的get方法

<script>
    let obj={ name:'Vue', age:8 }
    let obj2=new Proxy(obj,{
        /**target表示obj这个对象*property表示读取的属性的key*/
        get(target,property){
            console.log('执行了get');
            return target[property]
        }
    })
    console.log(obj2.age)
</script>

1. Proxy代理的set方法

<script>
    let obj={name:'Vue',age:8}
    let obj2=new Proxy(obj,{
        /**target表示obj这个对象*property表示读取的属性的key*newValue表示设置的值*/
        set(target,property,newValue){
            console.log('执行了set')
            target[property]=newValue
        }
    })
    obj2.age=7
    console.log(obj2.age)
</script>

2.了解Object.defineProperty

1. Object.defineProperty(对象.定义属性,用来为一个对象添加新属性)

<script>
    let person = {name:'张三',sex:'男',}
    // 为 person对象 传输了一个新属性 “age”，并且设定它的值为 18
    Object.defineProperty(person,'age',{value=18})
    console.log(person)
</script>

1. Object.defineProperty属性的可枚举可修改的实现

<script>
let person = {name:'张三',sex:'男',}
// 为 person对象 传输了一个新属性 “age”，并且设定它的值为 18
Object.defineProperty(person,'age',{
    enumerable=true  
    // 可枚举
    writable=true   
    // 可修改
    configurable:true 
    // 可删除
    value=18
})
console.log(person)
</script>

1. Object.defineProperty() 的get()方法

 <script>
    let person = {name: '张三',sex: '男',}
    function Observer(obj) {
        const keys = Object.keys(obj)
        keys.forEach((key) => {
            Object.defineProperty(this,key,{
                get() {return obj[key]}
            })
        })
    }
    const obs = new Observer(person)
    console.log(obs.sex);
</script>

1. Object.defineProperty() 的set()方法

<script>
    let person = { name: '张三', sex: '男', }
    function Observer(obj) {
      const keys = Object.keys(obj)
      keys.forEach((key) => {
        Object.defineProperty(this, key, {
          set(val) {
            console.log('set方法调用了')
            obj[key] = val
          }
        })
      })
    }
    const obs = new Observer(person)
    obs.name = 15
  </script>

3.Vue双向绑定的实现的对比

1. Vue3的Proxy实现

<body>
  <input type="text" id="ipt">
  <p id='op'></p>
  <script>
    function reactive(obj) {
      return new Proxy(obj, {
        get(target, property) {
          return target[property]
        },
        set(target, property, newVal) { target[property] = newVal }
      })
    } let newObj = reactive([1, 2])
    console.log(newObj[1])
    const ipt = document.querySelector('#ipt')
    ipt.value = newObj[1]
    document.querySelector('#op').innerHTML = newObj[1]
    ipt.addEventListener('input', function (e) {
      newObj[1] = e.target.valuedocument.querySelector('#op').innerHTML = newObj[1]
    })
  </script>
</body>

1. Vue2的Object.defineProperty实现

<body>
  <input type="text" id="ipt">
  <p id='op'></p>
  <script>
    function Observer(obj) {
      const keys = Object.keys(obj)
      keys.forEach((key) => {
        Object.defineProperty(this, key, {
          get() {
            console.log('get方法被调用了');
            return obj[key]
          },
          set(val) {
            console.log('set方法调用了')
            obj[key] = val
          }
        })
      })
    }
    const obs = new Observer([1, 2, 3])
    const ipt = document.querySelector('#ipt')
    ipt.value = obs[1]
    document.querySelector('#op').innerHTML = obs[1]
    ipt.addEventListener('input', function (e) {
      obs[1] = e.target.valuedocument.querySelector('#op').innerHTML = obs[1]
    })
  </script>
</body>

1. 上面的测试，Object.property是可以检测到通过索引改变数组的操作的，而Vue没有实现,Object.defineProperty表示这个锅我不背

内置组件

1.内置组件

(1)Teleport组件

1. 可以将一个组件内部的一部分模板“传送”到该组件的 DOM 结构外层的位置去
2. 父组件

<!-- 遮罩层组件传送到body下 -->
<script setup lang="ts">
  import Acom from './components/Acom.vue'
</script>
<template>
  <div class="app"></div>
  <Acom />
</template>
<style scoped>
  .app {
    width: 200px;
    height: 200px;
    background-color: pink;
  }
</style>

1. 子组件

<script setup lang="ts">
  import { ref } from 'vue'
  const open = ref(false)
</script>
<template>
  <button @click="open=true">显示遮罩层</button>
  <!-- 传送到body -->
  <Teleport to="body">
    <div class="cover" v-show="open">
      <span @click="open=false"> X</span>
    </div>
  </Teleport>
</template>
<style scoped>
  .cover {
    position: absolute;
    z-index: 2;
    top: 0;
    left: 0;
    bottom: 0;
    right: 0;
    background-color: rgba(0, 0, 0, 0.5);
  }
</style>

(2)Transition组件

1. 非命名动画

<script setup lang="ts">
  import { ref } from 'vue';
  const show = ref(true)
</script>
<template>
  <button @click="show=!show">显示/隐藏</button>
  <Transition>
    <div class="div" v-if="show"></div>
  </Transition>
</template>
<style scoped>
  .div {
    background-color: pink;
    width: 200px;
    height: 200px;
    margin: auto;
  }
 
  .v-enter-active,
  .v-leave-active {
    transition: opacity 0.5s ease;
  }
 
  .v-enter-from,
  .v-leave-to {
    opacity: 0;
  }
</style>

1. 命名动画

<script setup lang="ts">
  import { ref } from 'vue';
  const show = ref(true)
</script>
<template>
  <button @click="show=!show">显示/隐藏</button>
  <Transition name="fade">
    <div class="div" v-if="show"></div>
  </Transition>
</template>
<style scoped>
  .div {
    background-color: pink;
    width: 200px;
    height: 200px;
    margin: auto;
  }
 
  .fade-enter-active {
    transition: all 0.3s ease-out;
  }
 
  .fade-leave-active {
    transition: all 0.8s cubic-bezier(1, 0.5, 0.8, 1);
  }
 
  .fade-enter-from,
  .fade-leave-to {
    transform: translateX(20px);
    opacity: 0;
  }
</style>

1. 过度动画

<Transition mode="out-in">
...
</Transition>

1. 结合第三方库Animate.css

<!--  yarn add animate.css -->
<script setup lang="ts">
  import { ref } from 'vue'
  import 'animate.css'
  import Acom from './components/Acom.vue'
  const show = ref(true)
</script>
<template>
  <transition leave-active-class="animate__animated animate__fadeOut"
    enter-active-class="animate__animated animate__fadeIn">
    <Acom v-if="show"></Acom>
  </transition>
  <button @click="show = !show">显示/隐藏</button>
</template>
<style scoped lang="less"></style>

1. transition 生命周期

<script setup lang="ts">
  import { ref } from 'vue'
  import 'animate.css'
  import Acom from './components/Acom.vue'
  const show = ref(true)
  const beforeEnter = () => {
    console.log('进入之前')
  }
  const enter = (_, done: Function) => {
    console.log('过度曲线')
    setTimeout(() => { done() }, 3000)
  }
  const afterEnter = () => {
    console.log('过度完成')
  }
  const enterCancelled = () => {
    console.log('进入效果被打断')
  }
  const beforeLeave = () => {
    console.log('离开之前')
  }
  const leave = (_, done: Function) => {
    setTimeout(() => { done() }, 3000)
    console.log('过度曲线')
  }
  const afterLeave = () => {
    console.log('离开之后')
  }
  const leaveCancelled = () => {
    console.log('离开效果被打断')
  }
</script><template>
  <transition leave-active-class="animate__animated
    animate__fadeOut" enter-active-class="animate__animated animate__fadeIn" @before-enter="beforeEnter" @enter="enter"
    @after-enter="afterEnter" @enter-cancelled="enterCancelled" @before-leave="beforeLeave" @leave="leave"
    @after-leave="afterLeave" @leave-cancelled="leaveCancelled">
    <Acom v-if="show"></Acom>
  </transition>
  <button @click="show = !show">显示/隐藏</button>
</template>

1. 生命周期结合第三方库gsap.js

<!-- yarn add  gsap -->
<script setup lang="ts">
  import { ref } from 'vue'
  import Acom from './components/Acom.vue'
  import gsap from 'gsap'
  const show = ref(true)// 进入之前
  const beforeEnter = (el: Element) => {
    gsap.set(el, { width: 0, height: 0 })
  }
  // 进入过度动画
  const enter = (el: Element, done: gsap.Callback) => {
    gsap.to(el, { width: 200, height: 200, onComplete: done })
  }
  // 离开之前
  const beforeLeave = (el: Element) => {
    gsap.set(el, { width: 200, height: 200 })
  }
  // 进入过度动画
  const leave = (el: Element, done: gsap.Callback) => {
    gsap.to(el, { width: 0, height: 0, onComplete: done })
  }
</script><template>
  <transition@before-enter="beforeEnter"@enter="enter"@before-leave="beforeLeave"@leave="leave">
    <Acom v-if="show"></Acom>
    </transition>
    <button @click="show = !show">显示/隐藏</button>
</template>

1. 初始化动画

<script setup lang="ts">
  import { ref } from 'vue'
  import Acom from './components/Acom.vue'
  const show = ref(true)
</script><template>
  <transition appear-from-class="from" appear-active-class="active" appear-to-class="to" appear>
    <Acom v-if="show"></Acom>
  </transition>
  <button @click="show = !show">显示/隐藏</button>
</template>
<style scoped>
  .from {
    /* 初始化之前 */
    width: 0;
    height: 0;
  }
 
  .active {
    /* 过度动画 */
    transition: all 2s ease;
  }
 
  .to {
    /* 初始化完成 */
    width: 200px;
    height: 200px;
  }
</style>

1. 初始化动画结合Animate.css

<script setup lang="ts">
  import { ref } from 'vue'
  import Acom from './components/Acom.vue'
  import 'animate.css'
  const show = ref(true)
</script><template>
  <transition appear-active-class="animate__animated animate__heartBeat" appear>
    <Acom v-if="show"></Acom>
  </transition>
  <button @click="show = !show">显示/隐藏</button>
</template>
<style scoped></style>

(3)transition-group过度列表

1. Transition组件无法对v-for的列表进行渲染
2. transition-group的tag属性

<!-- tag属性可以让transition-group多加一层节点元素 -->
<template>
  <div class="wraps">
    <transition-group tag="session">
      <!-- 使用transition-group渲染的组件要有key-->
      <div class="item" v-for="item in 5" :key="item">{{ item }}</div>
    </transition-group>
  </div>
</template>

1. 添加列表时的动画效果

<script setup lang="ts">
  import { ref } from 'vue'
  import 'animate.css'
  const num = ref(5)
</script><template>
  <div class="wraps">
    <transition -groupleave-active-class="animate__animated animate__fadeOut"
      enter-active-class="animate__animated animate__fadeIn">
      <!-- 使用transition-group渲染的组件要有key-->
      <div class="item" v-for="item in num" :key="item">{{ item }}</div>
    </transition-group>
  </div>
  <button @click="num++">添加</button><button @click="num--">删除</button>
</template>
<style scoped lang="less">
  .wraps {
    display: flex;
    flex-wrap: wrap;
    word-break: break-all;
    border: 1px solid #ccc;
 
    .item {
      margin: 10px;
    }
  }
</style>

1. 平移动画move-class

<script setup lang="ts">
  import { ref } from 'vue'
  import _ from 'lodash'
  // 建立9x9数组
  let list = ref(Array.apply(null, { length: 81 } as number[]).map((_, index) => { return { id: index, number: (index % 9) + 1 } })
  )
  // 打乱数组
  const random = () => {
    list.value = _.shuffle(list.value)
  }
  console.log(list)
</script><template>
  <div><button @click="random">打乱</button>
    <transition-group tag="div" class="wraps" move-class="move">
      <div v-for="item in list" :key="item.id" class="item">{{ item.number }}</div>
    </transition-group>
  </div>
</template>
<style scoped lang="less">
  .wraps {
    display: flex;
    flex-wrap: wrap; // 换行
    width: calc(25px * 10 + 9px);.item {width: 25px;height: 25px;border: 1px solid #ccc;text-align: center;}
  }
 
  .move {
    transition: all 1s;
  }
</style>

1. 状态过度(数字过度颜色过度)

<script setup lang="ts">
  import { reactive, watch } from 'vue'
  import gsap from 'gsap'
  const num = reactive({
    current: 0, tweenedNumber: 0
  })
  watch(() => num.current, newVal => {
    gsap.to(num, {
      duration: 1, // 过度时间tweenedNumber: newVal
    })
  }
  )
</script><template>
  <div><input type="text" v-model="num.current" step="20" />
    <div>
      <!-- 去掉小数点 -->{{ num.tweenedNumber.toFixed(0) }}
    </div>
  </div>
</template>
<style scoped lang="less"></style>

(4)keep-alive组件

1. 开启keep-alive 生命周期的变化

初次进入时： onMounted-> onActivated
退出后触发:  deactivated

1. 缓存数据

<script setup lang="ts">
  import { ref } from 'vue'
  import Acom from './components/Acom.vue'
  const show = ref(true)
</script><template>
  <keep-alive>
    <Acom v-if="show"></Acom>
  </keep-alive>
  <button @click="show = !show">显示/隐藏</button>
</template>

1. include属性和exclude属性

<!-- 注意组件一定要命名才可以使用include -->
<script setup lang="ts">
  import { ref } from 'vue'
  import Acom from './components/Acom.vue'
  import Bcom from './components/Bcom.vue'
  const show = ref(true)
</script>
<template>
  <keep-alive :include="['Acom']" :exclude="['Bcom']">
    <Acom v-if="show"></Acom>
    <Bcom v-else></Bcom>
  </keep-alive><button @click="show = !show">显示/隐藏</button>
</template>

2.普通组件

(1)全局组件

1. 配置全局组件

<script setup lang="ts">
import { createApp } from 'vue'
import { createPinia } from 'pinia'
import App from './App.vue'
import Acom from './components/Acom.vue'
import './assets/main.css'
const app = createApp(App)
app.use(createPinia())
app.component('Acom', Acom)
app.mount('#app')
</script>

1. 使用组件

<template>
<div><Acom></Acom></div>
</template>

(2)异步组件

1. 子组件中发送了请求变成异步

<script setup lang="ts">
  interface ResItf {
    code: number
    data: { 
      a: number; 
      b: number 
    }[]
    message: string
  }
  let p: Promise<ResItf> = new Promise(resolve => {
    setTimeout(() => {}, 3000)
    resolve({
      code: 0,
      data: [{ a: 1, b: 2 },{ a: 11, b: 22 }],
      message: ''
    })
  })
  const a = await p
  console.log(a)
  </script><template><div>异步组件</div><div>异步组件</div><div>异步组件</div>
  </template>

1. 父组件异步调用组件

<script setup lang="ts">
  // 异步组件不能这样引入
  // import Acom from './components/Acom.vue'
  import { defineAsyncComponent } from 'vue'
  const Acom = defineAsyncComponent(() => import('./components/Acom.vue'))
</script>
<template>
  <div>
    <Suspense>
      <template #default>
        <Acom></Acom>
      </template>
      <template #fallback> 加载中。。。 </template>
    </Suspense>
  </div>
</template>
<style scoped lang="less"></style>

语法糖组件命名问题

1. 安装依赖yarn add vite-plugin-vue-setup-extend
2. 直接命名

<script lang="ts" setup name="xxx"></script>

常用的CSS的功能

1. 样式穿透

<style scoped lang="less">
:deep(input) {
    color: red;
}
</style>

1. 插槽选择器

<template>
  <div>
    <slot name="nums" :nums="['1', '2', '3']"> </slot>
  </div>
</template>
<style scoped lang="less">
  :slotted(.li) {
    color: red;
  }
</style>

1. 全局选择器

<script setup lang="ts"></script>
<template>
  <div>
    <slot name="nums" :nums="['1', '2', '3']"> </slot>
  </div>
</template>
<style scoped lang="less">
  :global(.li) {
    color: red;
  }
</style>

1. 动态CSS

<script setup lang="ts">
  import { reactive } from 'vue'
  const style = reactive({
    color: 'red'
  })
  setTimeout(() => {
    style.color = 'blue'
  }, 3000)
</script><template>
  <div class="div">动态css</div>
</template>
<style scoped lang="less">
  .div {
    color: v-bind('style.color');
  }
</style>

1.CSS原子化

1. 安装unocss yarn add unocss
2. vite的配置文件中配置

import { fileURLToPath, URL } from 'node:url'
    import pxtoViewPort from 'postcss-px-to-viewport'
    import { defineConfig } from 'vite'
    import unocss from 'unocss/vite'
    import vue from '@vitejs/plugin-vue'// https://vitejs.dev/config/
    export default defineConfig({
      plugins: [
        vue(),
        // 配置的原子化
        unocss({
          rules: [
            ['flex', { display: 'flex' }],
            ['red', { color: 'red' }],
            [/^m-(\d+)$/, ([, d]) => ({ margin: `${Number(d) * 10}px` })
            ]
          ]
        })
      ],
      resolve: {alias: {'@': fileURLToPath(new URL('./src', import.meta.url))}}
    })

1. main.ts中引入import 'uno.css'
2. 其他预设配置中引入

    import { fileURLToPath, URL } from 'node:url'
    import { defineConfig } from 'vite'
    import unocss from 'unocss/vite'
    import vue from '@vitejs/plugin-vue'
    import { presetIcons, presetAttributify, presetUno } from 'unocss'// https://vitejs.dev/config/
    export default defineConfig({
      plugins: [vue(), unocss({
        // 预设
        presets: [presetIcons(), presetAttributify(), presetUno()],
        rules: [
          ['flex', { display: 'flex' }],
          ['red', { color: 'red' }],
          [/^m-(\d+)$/, ([, d]) => ({ margin: `${Number(d) * 10}px` })]
        ]
      })],
      resolve: {alias: {'@': fileURLToPath(new URL('./src', import.meta.url))}}
    })

1. 第一预设图标库

npm i -D @iconify-json/ic
// 后缀ic是选择的图标库

1. 第二预设属性语义化 无须class

 <div color="red">left</div>

1. 第三预设

默认的 @unocss/preset-uno 预设（实验阶段）是一系列流行的原子化框架的 通用超集，
包括了 Tailwind CSS，Windi CSS，Bootstrap，Tachyons 等。
例如，ml-3（Tailwind），ms-2（Bootstrap），ma4（Tachyons），mt-10px（Windi CSS）均会生效。

5.Vue3集成Tailwind CSS

1. 安装依赖yarn add -D tailwindcss@latest postcss@latest autoprefixer@latest
2. 安装插件tailwind css inteliSence
3. 生成配置文件npx tailwindcss init -p
4. tailwind.config.js配置文件中添加

    /** @type {import('tailwindcss').Config} */
    module.exports = {
      content: ['./index.html', './src/**/*.{vue,js,ts,jsx,tsx}'], theme: { extend: {} }, plugins: []
    }

1. 创建index.css文件并且在mian.ts中引入

@tailwind base;
@tailwind components;
@tailwind utilities;

1. 使用tailwindcss的样式

  <script setup lang="ts"></script>
  <template>
    <div class="w-screen h-screen bg-red-600 flex justify-center items-center text-8xl text-teal-50">hello tailwind
    </div>
  </template>
  <style scoped lang="less"></style>

面试常用源码

1.app.use()的源码实现

1. 实现myuse

    import type { App } from 'vue'
    import { app } from '../main'
    interface Use {
      install: (app: App, ...options: any[]) => void
    }// 插件注册的数组
    const installList = new Set()
    export function MyUse<T extends Use>(plugin: T, ...options: any[]) {
      if (installList.has(plugin)) { 
        console.log('插件件已经注册')
        return 
      } 
      plugin.install(app, ...options)
      installList.add(plugin)
    }

1. 使用myuse调用插件

    import { createApp } from 'vue'
    import { createPinia } from 'pinia'
    import App from './App.vue'
    import './assets/main.css'
    import Loading from './components/Loading'
    import { MyUse } from './utils/myuse'
    export const app = createApp(App)
    // 使用插件
    // app.use(Loading)
    MyUse(Loading)
    app.use(createPinia())
    app.mount('#app')
    type Lod = {
      show: () => voidhide: () => void
    }
    //编写ts loading 声明文件放置报错 和 智能提示
    declare module '@vue/runtime-core' {
      export interface ComponentCustomProperties { $loading: Lod }
    }

移动端适配

1.第一种适配方案

1. 安装依赖yarn add amfe-flexible postcss postcss-pxtorem@5.1.1
2. main.ts引入amfe-flexibleimport "amfe-flexible"
3. 根目录下创建postcss.config.js文件并配置

    module.exports = {
      plugins: {
        'postcss-pxtorem': {
          // 能够把所有元素的px单位转成Rem
          // rootValue: 转换px的基准值。
          // 编码时, 一个元素宽是75px，则换成rem之后就是2rem
          rootValue: 37.5,
          propList: ['*']
        }
      }
    }

2.第二种适配方案

1. 安装依赖yarn add postcss-px-to-viewport -D
2. vite.config.ts内置postcss.config.js中修改配置

    import { fileURLToPath, URL } from 'node:url'
    import pxtoViewPort from 'postcss-px-to-viewport'
    import { defineConfig } from 'vite'
    import vue from '@vitejs/plugin-vue'// https://vitejs.dev/config/
    export default defineConfig({
      plugins: [vue()], css: {
        postcss: {
          plugins: [
            //postcss-px-to-viewport的配置
            pxtoViewPort({
              unitToConvert: 'px',  // 要转化的单位
              viewportWidth: 750,  // UI设计稿的宽度
              unitPrecision: 6, // 转换后的精度，即小数点位数
              propList: ['*'],// 指定转换的css属性的单位，*代表全部css属性的单位都进行转换
              viewportUnit: 'vw', // 指定需要转换成的视窗单位，默认vw
              fontViewportUnit: 'vw', // 指定字体需要转换成的视窗单位，默认vw
              selectorBlackList: ['ignore-'], // 指定不转换为视窗单位的类名              
              minPixelValue: 1, // 默认值1，小于或等于1px则不进行转换
              mediaQuery: true, // 是否在媒体查询的css代码中也进行转换，默认false
              replace: true,  // 是否转换后直接更换属性值
              landscape: false  // 是否处理横屏情况
            })
          ]
        }
      },
      resolve: {alias: {'@': fileURLToPath(new URL('./src', import.meta.url))}}
    })

1. 创建postcss-px-to-viewport.d.ts的声明文件

declare module 'postcss-px-to-viewport' {
      type Options = {
        unitToConvert: 'px' | 'rem' | 'cm' | 'em'
        viewportWidth: number
        viewportHeight: number // not now used; TODO: need for different units and math for different 
        propertiesunitPrecision: number
        viewportUnit: string
        fontViewportUnit: string // vmin is more suitable.
        selectorBlackList: string[]
        propList: string[]
        minPixelValue: number
        mediaQuery: boolean
        replace: boolean
        landscape: boolean
        landscapeUnit: string
        landscapeWidth: number
      }
      export default function (options: Partial<Options>): any
    }

1. 在tsconfig.json中引入声明文件

   {
      "extends": "@vue/tsconfig/tsconfig.web.json", 
      "include": ["env.d.ts", "src/**/*", "src/**/*.vue", "postcss-px-to-viewport.d.ts"], 
      "compilerOptions": { 
        "baseUrl": ".", 
        "types": ["element-plus/global"], 
        "paths": { "@/*": ["./src/*"] } 
      }, 
      "references": [{ "path": "./tsconfig.config.json" }]
    }

1. 注意:如果外面用到了postcss.config.js，在postcss.config.js中添加配置文件

    // 要禁用vite.config.ts内置postcss.config.js
    module.exports = {
      plugins: {
        tailwindcss: {}, 
        autoprefixer: {}, 
        'postcss-px-to-viewport': {
          unitToConvert: 'px', // 要转化的单位
          viewportWidth: 320, // UI设计稿的宽度// 
          unitPrecision: 6, // 转换后的精度，即小数点位数// 
          propList: ['*'], // 指定转换的css属性的单位，*代表全部css属性的单位都进行转换// 
          viewportUnit: 'vw', // 指定需要转换成的视窗单位，默认vw// 
          fontViewportUnit: 'vw', // 指定字体需要转换成的视窗单位，默认vw// 
          selectorBlackList: ['wrap'], // 指定不转换为视窗单位的类名，// 
          minPixelValue: 1, // 默认值1，小于或等于1px则不进行转换// 
          mediaQuery: true, // 是否在媒体查询的css代码中也进行转换，默认false// 
          replace: true, // 是否转换后直接更换属性值// 
          exclude: [/node_modules/], // 设置忽略文件，用正则做目录名匹配// 
          landscape: false // 是否处理横屏情况
        }
      }
    }

的其他知识点

1.全局函数和全局变量

1. 全局函数

    import { createApp } from 'vue'
    import { createPinia } from 'pinia'
    import App from './App.vue'
    import './assets/main.css'
    const app = createApp(App)
    type Fileter = {
      format: <T>(str: T) => string
    }
    declare module '@vue/runtime-core' {
      export interface ComponentCustomProperties { $filters: Fileter }
    }
    // 全局函数
    app.config.globalProperties.$filters = {
      format<T>(str: T): string { return `真${str}` }
    }
    app.use(createPinia())
    app.mount('#app')

1. 全局变量

import { createApp } from 'vue'
import { createPinia } from 'pinia'
import App from './App.vue'
import './assets/main.css'
const app = createApp(App)
declare module '@vue/runtime-core' {
    export interface ComponentCustomProperties {$env: string}
}
// 全局变量
app.config.globalProperties.$env = '全局变量'
app.use(createPinia())
app.mount('#app')

2.自定义插件

1. 封装插件的样式，抛出插件的显示隐藏方法

<script setup lang="ts">
import { ref } from 'vue'
const isShow = ref(false)
// 控制load显示
const show = () => {
    console.log(111)isShow.value = true
}
const hide = () => {
    isShow.value = false
}
// 这里抛出的东西会在插件声明文件中调用
defineExpose({show,hide})
</script>
<template>
<div v-if="isShow" class="loading">loading....</div>
</template>
<style scoped lang="less"></style>

1. 创建接收调用插件的方法

    import { render, type App, type VNode } from 'vue'
    import Loading from './index.vue'
    import { createVNode } from 'vue'
    export default {
      install(app: App) {
        // 变成div
        const Vnode: VNode = createVNode(Loading)
        // 挂载
        render(Vnode, document.body)
        // console.log(app, Vnode)// 
        // 读取loading组件中导出的方法// 
        console.log(Vnode.component?.exposed.show)
        // 对插件的方法进行全局挂载
        app.config.globalProperties.$loading = {
          show: Vnode.component?.exposed?.show,
          hide: Vnode.component?.exposed?.hide
        }
      }
    }

1. main.ts中挂载上面的方方法

import { createApp } from 'vue'
import { createPinia } from 'pinia'
import App from './App.vue'
import './assets/main.css'
import Loading from './components/Loading'
const app = createApp(App)
// 使用插件
app.use(Loading)
app.use(createPinia())
app.mount('#app')

1. 对插件的方法进行声明

type Lod = {
    show: () => void
    hide: () => void
}
//编写ts loading 声明文件放置报错 和 智能提示
declare module '@vue/runtime-core' {
    export interface ComponentCustomProperties {$loading: Lod}
}

1. 使用插件

<script setup lang="ts">
  import { getCurrentInstance } from 'vue'
  const instance = getCurrentInstance()
  // 调用插件
  instance?.proxy?.$loading.show()
  // 5秒关闭插件
  setTimeout(() => {
    instance?.proxy?.$loading.hide()
  }, 5000)
</script>
<template>
  <div></div>
</template>
<style scoped lang="less"></style>

3.函数式编程

1. h函数

h 接收三个参数
1.type 元素的类型
2.propsOrChildren 数据对象, 这里主要表示(props, attrs, dom props, class 和 style)
3.children 子节点

1. h函数的多种组合

// 除类型之外的所有参数都是可选的
h('div')
h('div', { id: 'foo' })//属性和属性都可以在道具中使用
//Vue会自动选择正确的分配方式
h('div', { class: 'bar', innerHTML: 'hello' })
// props modifiers such as .prop and .attr can be added
// with '.' and `^' prefixes respectively
h('div', { '.name': 'some-name', '^width': '100' })// class 和 style 可以是对象或者数组
h('div', { class: [foo, { bar }], style: { color: 'red' } })// 定义事件需要加on 如 onXxx
h('div', { onClick: () => {} })// 子集可以字符串
h('div', { id: 'foo' }, 'hello')//如果没有props是可以省略props 的
h('div', 'hello')
h('div', [h('span', 'hello')])// 子数组可以包含混合的VNode和字符串
h('div', ['hello', h('span', 'hello')])

1. 使用props传递参数

<template>
  <Btn text="按钮"></Btn>
</template>
<script setup lang='ts'>
  import { h, } from 'vue';
  type Props = {
    text: string
  }
  const Btn = (props: Props, ctx: any) => {
    return h('div', { 
      class: 'p-2.5 text-white bg-green-500 rounded shadow-lg w-20 text-center inline m-1', 
    }, 
    props.text)
  }
</script>

1. 接收emit

<template>
  <Btn @on-click="getNum" text="按钮"></Btn>
</template>
<script setup lang='ts'>
  import { h, } from 'vue';
  type Props = {
    text: string
  }
  const Btn = (props: Props, ctx: any) => {
    return h('div', { 
      class: 'p-2.5 text-white bg-green-500 rounded shadow-lg w-20 text-center inline m-1', 
      onClick: () => { ctx.emit('on-click', 123) } 
    }, props.text)
  }
  const getNum = (num: number) => {
    console.log(num);
  }
</script>

1. 定义插槽

<template>
  <Btn @on-click="getNum">
    <template #default>按钮slots</template>
  </Btn>
</template>
<script setup lang='ts'>
  import { h, } from 'vue';
  type Props = {
    text?: string
  }
  const Btn = (props: Props, ctx: any) => {
    return h('div', { 
      class: 'p-2.5 text-white bg-green-500 rounded shadow-lg w-20 text-center inline m-1', 
      onClick: () => { ctx.emit('on-click', 123) } 
    }, ctx.slots.default())
  }
  const getNum = (num: number) => {
    console.log(num);
  }
</script>

4.vue性能优化

(1)跑分和打包体积

1. 跑分vue开发工具Lighthouse

从Performance页的表现结果来看，得分37分，并提供了很多的时间信息，
我们来解释下这些选项代表的意思：FCP (First Contentful Paint)：
首次内容绘制的时间，浏览器第一次绘制DOM相关的内容，也是用户第一次看到页面内容的时间。
 
Speed Index: 页面各个可见部分的显示平均时间，
当我们的页面上存在轮播图或者需要从后端获取内容加载时，这个数据会被影响到。
 
LCP (Largest Contentful Paint)：最大内容绘制时间，页面最大的元素绘制完成的时间。
 
TTI（Time to Interactive）：从页面开始渲染到用户可以与页面进行交互的时间，
内容必须渲染完毕，交互元素绑定的事件已经注册完成。
 
TBT（Total Blocking Time）：记录了首次内容绘制到用户可交互之间的时间，
这段时间内，主进程被阻塞，会阻碍用户的交互，页面点击无反应。
 
CLS（Cumulative Layout Shift）：计算布局偏移值得分，会比较两次渲染帧的内容偏移情况，
可能导致用户想点击A按钮，但下一帧中，A按钮被挤到旁边，导致用户实际点击了B按钮。

1. 打包后rollup的插件yarn add rollup-plugin-visualizer

  import { fileURLToPath, URL } from 'node:url'
  import { defineConfig, loadEnv } from 'vite'
  import unocss from 'unocss/vite'
  import vue from '@vitejs/plugin-vue'
  import { visualizer } from 'rollup-plugin-visualizer'// https://vitejs.dev/config/
  export default ({ mode }: any) => {
    console.log(loadEnv(mode, process.cwd()))
    return defineConfig({
      plugins: [
        vue(), // 配置rollup的插件
        visualizer({ open: true })
      ], 
      resolve: { alias: { '@': fileURLToPath(new URL('./src', import.meta.url)) } }
    })
  }

1. vite配置文件中vite的优化

  import { fileURLToPath, URL } from "node:url";
  import { defineConfig } from "vite";
  import vue from "@vitejs/plugin-vue";
  import vueJsx from "@vitejs/plugin-vue-jsx";// https://vitejs.dev/config/
  export default defineConfig({ 
    ...
    build: { 
      chunkSizeWarningLimit: 2000, 
      cssCodeSplit: true, //css 拆分
      sourcemap: false, //不生成sourcemap
      minify: 'terser', //是否禁用最小化混淆，esbuild打包速度最快，terser打包体积最小。
      assetsInlineLimit: 5000 //小于该值 图片将打包成Base64
    }
  })

(2)PWA离线存储技术

1. 安装依赖yarn add vite-plugin-pwa -D
2. 配置

  import { fileURLToPath, URL } from "node:url";
  import { VitePWA } from "vite-plugin-pwa";
  import { defineConfig } from "vite";
  import vue from "@vitejs/plugin-vue";
  import vueJsx from "@vitejs/plugin-vue-jsx";// https://vitejs.dev/config/
  export default defineConfig({
    plugins: [vue(), vueJsx(), VitePWA({
      workbox: {
        cacheId: "key", //缓存名称
        runtimeCaching: [{
          urlPattern: /.*\.js.*/, //缓存文件
          handler: "StaleWhileRevalidate", //重新验证时失效
          options: {
            cacheName: "XiaoMan-js", //缓存js，名称
            expiration: {
              maxEntries: 30, //缓存文件数量 LRU算法
              maxAgeSeconds: 30 * 24 * 60 * 60, //缓存有效期
            },
          },
        }],
      },
    })],
    ...
  });

(3)其他性能优化

1. 图片懒加载

import { createApp } from 'vue'
import App from './app'
import lazyPlugin from 'vue3-lazy'
const app = createApp(App)
app.use(lazyPlugin, {loading: 'loading.png',error: 'error.png'})
app.mount('#app')
 
<img v-lazy="user.avatar" >

1. 虚拟列表实现

后台返回多数据
展示可视区的dom

1. 多线程 使用 new Worker 创建

// worker脚本与主进程的脚本必须遵守同源限制。他们所在的路径协议、域名、端口号三者需要相同
const myWorker1 = new Worker("./calcBox.js");
// 都使用postMessage发送消息
worker.postMessage(arrayBuffer, [arrayBuffer]);
// 都使用onmessage接收消息
self.onmessage = function (e) {
// xxx这里是worker脚本的内容
};
关闭worker.terminate();