vueUse拖拽

拖拽

适用于一些点击后拖拽的场景

npm i @vueuse/core

<div ref="target">
     <img ref="boxRef">
 div>

import {computed, onMounted, reactive, ref} from 'vue'
import {useMouseInElement} from '@vueuse/core'

const target = ref(null)  // 父元素的引用
const boxRef = ref(null)  // 拖拽的目标元素的引用
const canDrag = ref(false)   // 目标元素是否能被拖拽

const mousePosition = reactive({
    left: 0,
    top: 0
})
// 拖拽元素的位置
const position = reactive({
    left: '0px',
    top: '0px'
})

// 使用@vueuse/core获取目标元素在父元素中的位置
const {elementX, elementY, isOutside} = useMouseInElement(target)

onMounted(() => {
    if (boxRef.value) {
        // 获取鼠标在拖拽元素内的坐标
        boxRef.value.onmousedown = (e) => {
            mousePosition.left = e.clientX - target.value.offsetLeft - boxRef.value.offsetLeft
            mousePosition.top = e.clientY - target.value.offsetTop - boxRef.value.offsetTop
            boxRef.value.onmousemove = () => {
                canDrag.value = true
            }
        }

        document.documentElement.onmouseup = () => {
            boxRef.value && (boxRef.value.onmousemove = null);
            canDrag.value = false
        }
    }
})

watch([elementX, elementY, isOutside], () => {
    if (!canDrag.value) return

    // 鼠标在图片的区域之外，不需要计算坐标
    if (isOutside.value) return

    position.left = elementX.value - mousePosition.left
    position.top = elementY.value - mousePosition.top

    position.left += 'px'
    position.top += 'px'
})