Vue3 composition API实现逻辑复用的方法

// useMousePosition.js
import { ref, onMounted, onUnmounted } from 'vue'

// 1. 定义一个函数,抽离逻辑，命名使用 useXXX
function useMousePosition() {
  // 使用ref定义
  const x = ref(0)
  const y = ref(0)

  function update(e) {
    console.log(x.value, y.value);

    x.value = e.pageX
    y.value = e.pageY
  }

  onMounted(() => {
    console.log('开始监听鼠标划动事件');
    window.addEventListener('mousemove', update)
  })

  onUnmounted(() => {
    console.log('解除监听鼠标划动事件');
    window.removeEventListener('mousemove', update)
  })
  return {
    x, 
    y
  }
}

 
// 导出这个函数
export default useMousePosition

<!-- 在任意一个组件,都可以调用这个方法 -->

<template>
  <p>mouse position: {{x}}, {{y}}</p>
</template>

<script>
import useMousePosition from './useMousePosition'
export default {
  name: 'MousePosition', 
  setup() {
    // useMousePosition是使用ref定义变量的,这种可以解构
    const { x, y } = useMousePosition()
    console.log(x, y)
    return {
      x, y
    }
  }
}
</script>

import {  onMounted, onUnmounted, reactive } from 'vue'

export function useMousePosition2() {
  // 使用reactive定义
  const mouse = reactive({
    x: 0, 
    y: 0
  })

  function update(e) {
    mouse.x = e.pageX
    mouse.y = e.pageY
  }

  onMounted(() => {
    console.log('开始监听鼠标划动事件');
    window.addEventListener('mousemove', update)
  })

  onUnmounted(() => {
    console.log('解除监听鼠标划动事件');
    window.removeEventListener('mousemove', update)
  })

  return {
    mouse
  }
}
<template>
  <!-- 使用对象方式显示信息 -->
  <p>mouse position2: {{mouse.x}}, {{mouse.y}}</p>
</template>
<script>
import { useMousePosition2 } from './useMousePosition'
export default {
  name: 'MousePosition', 
  setup() {
    // useMousePosition2是使用reactive定义的,这种不可以解构
    const { mouse } = useMousePosition2()
    return {
      mouse
    }
  }
}
</script>

export function useMousePosition3() {
  // 使用reactive定义
  const mouse = reactive({
    x: 0, 
    y: 0
  })

  function update(e) {
    mouse.x = e.pageX
    mouse.y = e.pageY
  }

  onMounted(() => {
    console.log('开始监听鼠标划动事件');
    window.addEventListener('mousemove', update)
  })

  onUnmounted(() => {
    console.log('解除监听鼠标划动事件');
    window.removeEventListener('mousemove', update)
  })
  
  // 这里，使用toRefs解构成ref对象
  return toRefs(mouse)
}
<template>
  <p>mouse position: {{x}}, {{y}}</p>
</template>

<script>
import { useMousePosition3 } from './useMousePosition'
export default {
  name: 'MousePosition', 
  setup() {
    // 使用reactive定义鼠标坐标对象，然后通过toRefs将其解构成ref对象
    const { x, y } = useMousePosition()
    console.log(x, y)
    return {
      x, y
    }
  }
}
</script>