1.shallowRef与shallowReactive

<template>
  <div class="app">
    <h2>求和为:{{ sum }}</h2>
    <h2>名字为:{{ person.name }}</h2>
    <h2>年龄为:{{ person.age }}</h2>
    <button @click="sum += 1">sum+1</button>
    <button @click="updateName">修改名字u</button>
    <button @click="updateAge">修改年龄</button>
    <button @click="update">修改整个人</button>

    <hr />
    <h2>汽车名称:{{ car }}</h2>
    <button @click="updateCarName">修改起床名字</button>
    <button @click="updateCarColor">修改颜色</button>
    <button @click="updateCar">修改整个车</button>
  </div>
</template>

<script setup lang="ts" name="App">
import { ref, reactive, shallowRef, shallowReactive } from "vue";

let sum = shallowRef(0); //浅层次变成响应式 等号改变的才有响应式
let person = shallowRef({
  name: "张三",
  age: 18,
});
let car = shallowReactive({//只有第一层有效果,深层次无响应式
  name: "宝马",
  options: {
    color: "红色",
    engine: "V8",
  },
});
function update() {
  person.value = { name: "王五", age: 20 };
}
function updateName() {
  person.value = { name: "王五", age: person.value.age };
}
function updateAge() {
  person.value = { name: person.value.name, age: 13 };
}

function updateCar() {}
function updateCarName() {
  car.name = "奔驰";
}
function updateCarColor() {
  car.options.color = "red";
}
</script>



<style>
.app {
  background-color: #ddd;
  border-radius: 10px;
  box-shadow: 0 0 10px;
  padding: 10px;
}
button {
  margin: 0 10px;
}
</style>

 2.readonly与shallowReadonly

 

<template>
  <div class="app">
    <h2>当前求和为:{{ sum }}</h2>
    <h2>当前求和为:{{ sum2 }}</h2>
	<button @click="changeSum">点我加一</button>
	<button @click="changeSum2">点我加一</button>
  </div>
</template>

<script setup lang="ts" name="App">
import { ref, readonly,shallowReadonly } from "vue";
let sum = ref(0);

let sum2 = readonly(sum);//不仅仅能让ref不能改 reactive也不能改
console.log(sum2.value);//0
// shallowReadonly//浅层只读 第一层只读，深层可以改
function changeSum(){
	sum.value += 1;
}
function changeSum2(){
	sum2.value += 1;//不允许改的/Cannot assign to 'value' because it is a read-only property.
}


</script>



<style>
.app {
  background-color: #ddd;
  border-radius: 10px;
  box-shadow: 0 0 10px;
  padding: 10px;
}
button {
  margin: 0 10px;
}
</style>

3.toRaw与markRaw

 

<template>
  <div class="app">
	<h2> 姓名:{{ person.name }}</h2>
	<h2> 年龄:{{ person.age }}</h2>
	<button @click="update1">修改响应式</button>
	<button @click="update2">修改普通</button>
  </div>
</template>

<script setup lang="ts" name="App">
import { ref, reactive,toRaw ,markRaw} from "vue";

let person = reactive({
  name: '张三',
  age: 18,
})
let p = toRaw(person);//将响应式对象变成普通对象
//markRaw 是一个对象永远变不了响应式
console.log(person);
console.log(p);//可以改，是同一个对象，改了下一次渲染模板页面也会带着它的值

function update1(){
  person.name = '李四';
  p.age = 20;
}
function update2(){
	person.name = '王五';
  p.age = 22;
}

</script>



<style>
.app {
  background-color: #ddd;
  border-radius: 10px;
  box-shadow: 0 0 10px;
  padding: 10px;
}
button {
  margin: 0 10px;
}
</style>

 mockjs 是模仿后端的接口

4.自定义Ref  customRef

 

import { customRef } from "vue";


export default function(initValue:string,delay:number){
    //使用Vue提供的默认ref定义
// let msg = ref('你好')

//使用Vue提供的customRef定义响应式数据
let timer:any;
//track (跟踪) trigger(触发)
let msg = customRef((track, trigger) => {
  return {
    //get 何时调用? --msg 被读取
    get() {
      track(); //告诉vue 数据msg很重要，你要对msg进行持续关注, 一旦msg变化，就去更新
      return initValue;
    },
    //set 何时调用 ? --msg 被修改
    set(value) {
      clearTimeout(timer);
      timer = setTimeout(() => {
        initValue = value;
        trigger(); //通知vue一下数据msg变化了
      }, delay);
    },
  };
});

return {msg}
}

<template>
  <div class="app">
    <h2>{{ msg }}</h2>
    <input type="text" v-model="msg" />
  </div>
</template>

<script setup lang="ts" name="App">
 import userMsgRef from './userMsgRef';

 let {msg} = userMsgRef('你好',1000);
</script>



<style>
.app {
  background-color: #ddd;
  border-radius: 10px;
  box-shadow: 0 0 10px;
  padding: 10px;
}
button {
  margin: 0 10px;
}
</style>

5.Vue3新组件

1.Teleport

<template>
  <button @click="isShow = true">展示弹窗</button>
  <!-- #app . html -->
  <teleport to="body">
    <!-- 传送到body下了 -->
    <div class="model" v-show="isShow">
      <h2>我是弹窗的标题</h2>
      <p>我是弹窗的内容</p>
      <button @click="isShow = false">关闭弹窗</button>
    </div>
  </teleport>
</template>

<script setup lang="ts" name="Model">
import { ref } from "vue";
let isShow = ref(false);
</script>

<style lang="css" scoped>
.model {
  width: 200px;
  height: 150px;
  background-color: skyblue;
  border-radius: 10px;
  padding: 5px;
  box-shadow: 0 0 5px;
  text-align: center;
  position: fixed;
  left: 50%;
  margin-left: -100px;
  top: 20px;
}
</style>

 

<template>
  <div class="outer">
	<h2>我是App组件</h2>
	<img src="https://tse1-mm.cn.bing.net/th/id/OIP-C.Zte3ljd4g6kqrWWyg-8fhAHaEo?w=303&h=189&c=7&r=0&o=5&pid=1.7" alt="">
	<br>
	<Model/>
  </div>
</template>

<script setup lang="ts" name="App">
	import Model from './Model.vue';
</script>



<style scoped>
.outer {
  background-color: #ddd;
  border-radius: 10px;
  box-shadow: 0 0 10px;
  padding: 10px;
  width: 400px;
  height: 400px;
  /**饱和度滤镜 */
  filter: saturate(200%);
}
img {
  width: 270px;
}
</style>

2.Suspense

UomgAPI - 优启梦免费API数据接口调用服务平台

推荐这个开放Api网站

<template>
  <div class="app">
	<h2>我是App组件</h2>
	<Suspense>
		<template #default>
			<!-- 异步任务做完的时候出现 -->
			<Child/>
		</template>
		<template #fallback>
			<!-- 异步任务没有做完的时候出现 -->
			<div>加载中...</div>
		</template>
	</Suspense>
	
  </div>
</template>

<script setup lang="ts" name="App">
import { Suspense } from 'vue';
import Child from './Child.vue';

</script>



<style scoped>
.app {
  background-color: #ddd;
  border-radius: 10px;
  box-shadow: 0 0 10px;
  padding: 10px;
}

</style>

<template>
    <div class="child">
            <h2>我是Child组件</h2>
            <h2>当前求和为:{{sum}}</h2>
    </div>
</template>

<script setup lang="ts" name="">
import { ref } from "vue" 
import axios from "axios";
let sum = ref(0);

let {data:{content}} = await axios.get('https://api.uomg.com/api/rand.qinghua')

console.log(content);


</script>

<style lang="css" scoped>
    .child{
        background-color: skyblue;
        border-radius: 10px;
        box-shadow: 0 0 10px;
        padding: 10px;
    }
</style>

3.全局Api转移到应用对象

Vue3 Api

app.component 定义全局组件 

import {createApp} from 'vue'
import App from './App.vue'
import Hello from './Hello.vue'

// 创建应用
const app = createApp(App)

app.component('Hello',Hello)

//全局变量
app.config.globalProperties.x=99;

declare module 'vue'{
    interface ComponentCustomProperties{
        x:number
    }
}
//全局自定义指令 v-beauty
app.directive('beauty',(element,{value})=>{
    element.innerText +=value;
    element.style.color='red'
    element.style.backgroundColor='yellow'
})


app.mount('#app')

setTimeout(()=>{
    //卸载
    app.unmount()
},3000)

// 使用插件
// app.use(router)

 4.其他

记得看这个 

 

 完结撒花