链接上一篇文章：vue3学习之侦测变化watch

1、使用鼠标监听，如下：

<template>
  <div id="app">
    <img alt="Vue logo" src="./assets/logo.png">
    <h1>{{count}}</h1>
    <h1>{{double}}</h1>
    <h1>x:{{x}}</h1>
    <h1>y:{{y}}</h1>
    <ul>
      <li v-for="number in numbers" :key="number">
        <h1>{{number}}</h1>
      </li>
    </ul>
    <h1>{{person.name}}</h1>
    <button @click="increase">赞+1</button><br/>
    <button @click="updateGreeting">Update Title</button>
  </div>
</template>

<script lang="ts">
  // 响应式对象引入,计算函数引入
import { ref,computed,reactive,toRefs,onMounted,onUpdated,watch,onUnmounted } from 'vue'

interface DataProps {
  count: number;
  double: number;
  increase: () => void;
  numbers: Array<number>,
  person: {name ? :string}
}

export default{
  name: 'App',
  setup() {

    onUpdated(() => {
      console.log('onUpdated');
    })
    // onRenderTracked((event) => {
    //   console.log(event);
    // })

    const data: DataProps  = reactive({
      count: 0,
      increase: () => { data.count++},
      double: computed(() => data.count * 2),
      numbers: [0,1,2],
      person: {}
    })
    const greetings = ref('')
    const updateGreeting = () => {
      greetings.value += 'Hello! '
    }
    const x = ref(0)
    const y = ref(0)
    const updateMouse = (e:MouseEvent)=> {
      x.value = e.pageX
      y.value = e.pageY
    }
    onMounted(() => {
      document.addEventListener('click',updateMouse)
    })
    onUnmounted(()=>{
      document.removeEventListener('click',updateMouse)
    })
    watch([greetings,()=> data.count], (newValue,oldValue) => {
      console.log('old',oldValue)
      console.log('new',newValue)
      document.title = 'update' + greetings.value + data.count
    })
    data.numbers[0] = 5;
    data.person.name = 'haijin';
    const refData = toRefs(data)
    return {
      ...refData,
      greetings,
      updateGreeting,
      x,
      y
    }
  }
};
</script>

<style>
#app {
  font-family: Avenir, Helvetica, Arial, sans-serif;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-align: center;
  color: #2c3e50;
  margin-top: 60px;
}
</style>

2、vue3的重用：我们新建一个文件夹hooks，在文件夹中编写一个文件useMousePosition.ts

如图：

useMousePosition.ts代码如下：

import { ref, onMounted, onUnmounted } from 'vue'
function useMousePosition() {
  const x = ref(0)
  const y = ref(0)
  const updateMouse = (e: MouseEvent) => {
    x.value = e.pageX
    y.value = e.pageY
  }
  onMounted(() => {
    document.addEventListener('click', updateMouse)
  })
  onUnmounted(() => {
    document.removeEventListener('click', updateMouse)
  })
  return {x, y}
}

export default useMousePosition

这就是刚刚我们监听鼠标的相关代码，现在我们抽离了出来，我们就能够进行很好的复用了。

然后我们在我们需要复用的地方导入import useMousePosition from './hooks/useMousePosition

然后我们就可以自由的使用了const { x, y } = useMousePosition()

整体代码如下：

<template>
  <div id="app">
    <img alt="Vue logo" src="./assets/logo.png">
    <h1>{{count}}</h1>
    <h1>{{double}}</h1>
    <h1>x:{{x}}</h1>
    <h1>y:{{y}}</h1>
    <ul>
      <li v-for="number in numbers" :key="number">
        <h1>{{number}}</h1>
      </li>
    </ul>
    <h1>{{person.name}}</h1>
    <button @click="increase">赞+1</button><br/>
    <button @click="updateGreeting">Update Title</button>
  </div>
</template>

<script lang="ts">
  // 响应式对象引入,计算函数引入
import { ref,computed,reactive,toRefs,onMounted,onUpdated,watch,onUnmounted } from 'vue'
import useMousePosition from './hooks/useMousePosition'

interface DataProps {
  count: number;
  double: number;
  increase: () => void;
  numbers: Array<number>,
  person: {name ? :string}
}

export default{
  name: 'App',
  setup() {

    onUpdated(() => {
      console.log('onUpdated');
    })
    // onRenderTracked((event) => {
    //   console.log(event);
    // })

    const data: DataProps  = reactive({
      count: 0,
      increase: () => { data.count++},
      double: computed(() => data.count * 2),
      numbers: [0,1,2],
      person: {}
    })
    const { x, y } = useMousePosition()
    const greetings = ref('')
    const updateGreeting = () => {
      greetings.value += 'Hello! '
    }
    // const x = ref(0)
    // const y = ref(0)
    // const updateMouse = (e:MouseEvent)=> {
    //   x.value = e.pageX
    //   y.value = e.pageY
    // }
    // onMounted(() => {
    //   document.addEventListener('click',updateMouse)
    // })
    // onUnmounted(()=>{
    //   document.removeEventListener('click',updateMouse)
    // })
    watch([greetings,()=> data.count], (newValue,oldValue) => {
      console.log('old',oldValue)
      console.log('new',newValue)
      document.title = 'update' + greetings.value + data.count
    })
    data.numbers[0] = 5;
    data.person.name = 'haijin';
    const refData = toRefs(data)
    return {
      ...refData,
      greetings,
      updateGreeting,
      x,
      y
    }
  }
};
</script>

<style>
#app {
  font-family: Avenir, Helvetica, Arial, sans-serif;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-align: center;
  color: #2c3e50;
  margin-top: 60px;
}
</style>