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10个Vue项目必备的高频实用自定义指令(复制即用)

作者:前端Hardy

在实际开发中,很多重复逻辑用自定义指令来做最优雅,既不污染组件,复用性又极强, 所以本文小编为大家整理了 10 个企业级最常用的 Vue 自定义指令,复制到项目就能直接用,建议收藏进你的工具库

在实际开发中,很多重复逻辑(权限控制、防抖点击、图片懒加载、文本复制等)用自定义指令来做最优雅,不污染组件、不写冗余代码、复用性极强。

今天整理了 10 个企业级最常用的 Vue 自定义指令,Vue2 / Vue3 都能跑,复制到项目里直接用,建议收藏进你的工具库。

1. v-permission 按钮权限控制(后台系统必用)

根据权限码控制按钮显隐,后端返回权限列表直接用。

// directives/permission.js
import { useUserStore } from '@/stores/user'

export default {
  mounted(el, binding) {
    const { permissions } = useUserStore()
    const value = binding.value
    if (!value) return
    // 无权限则移除元素
    if (!permissions.includes(value)) {
      el.parentNode?.removeChild(el)
    }
  }
}

使用:

<button v-permission="'user:add'">添加用户</button>

2. v-debounce 防抖点击(搜索/提交防重复)

// directives/debounce.js
export default {
  mounted(el, binding) {
    const { func, delay = 300 } = binding.value
    let timer = null
    el.addEventListener('click', () => {
      clearTimeout(timer)
      timer = setTimeout(() => func(), delay)
    })
  }
}

使用:

<button v-debounce="{ func: handleSearch, delay: 500 }">搜索</button>

3. v-throttle 节流指令(滚动/防狂点)

// directives/throttle.js
export default {
  mounted(el, binding) {
    const { func, delay = 500 } = binding.value
    let lastTime = 0
    el.addEventListener('click', () => {
      const now = Date.now()
      if (now - lastTime >= delay) {
        func()
        lastTime = now
      }
    })
  }
}

4. v-copy 一键复制文本

// directives/copy.js
export default {
  mounted(el, binding) {
    el.addEventListener('click', () => {
      const text = binding.value
      navigator.clipboard.writeText(text).then(() => {
        ElMessage.success('复制成功')
      })
    })
  }
}

使用:

<span v-copy="orderNo">复制订单号</span>

5. v-longpress 长按指令

// directives/longpress.js
export default {
  mounted(el, binding) {
    const { func, time = 1000 } = binding.value
    let timer = null
    el.addEventListener('mousedown', () => {
      timer = setTimeout(() => func(), time)
    })
    el.addEventListener('mouseup mouseleave', () => clearTimeout(timer))
  }
}

6. v-input-number 仅允许输入数字(支持小数)

// directives/number.js
export default {
  mounted(el) {
    const input = el.tagName === 'INPUT' ? el : el.querySelector('input')
    input.addEventListener('input', () => {
      input.value = input.value.replace(/[^\d.]/g, '')
      const arr = input.value.split('.')
      if (arr.length > 2) input.value = arr[0] + '.' + arr[1]
    })
  }
}

使用:

<el-input v-input-number v-model="num" />

7. v-lazy 图片懒加载(性能优化)

// directives/lazy.js
export default {
  mounted(el, binding) {
    const observer = new IntersectionObserver(([{ isIntersecting }]) => {
      if (isIntersecting) {
        el.src = binding.value
        observer.unobserve(el)
      }
    })
    observer.observe(el)
  }
}

使用:

<img v-lazy="imgUrl" alt="" />

8. v-draggable 元素拖拽

// directives/drag.js
export default {
  mounted(el) {
    el.style.cssText += ';position:fixed;cursor:move;'
    el.addEventListener('mousedown', (e) => {
      const x = e.clientX - el.offsetLeft
      const y = e.clientY - el.offsetTop
      const move = (e) => {
        el.style.left = e.clientX - x + 'px'
        el.style.top = e.clientY - y + 'px'
      }
      document.addEventListener('mousemove', move)
      document.addEventListener('mouseup', () => {
        document.removeEventListener('mousemove', move)
      }, { once: true })
    })
  }
}

9. v-watermark 页面水印(防截图)

// directives/watermark.js
export default {
  mounted(el, binding) {
    const text = binding.value || '内部资料'
    const canvas = document.createElement('canvas')
    canvas.width = 200
    canvas.height = 150
    const ctx = canvas.getContext('2d')
    ctx.font = '14px Arial'
    ctx.fillStyle = 'rgba(0,0,0,0.1)'
    ctx.rotate(-0.2)
    ctx.fillText(text, 20, 50)
    el.style.background = `url(${canvas.toDataURL()}) repeat`
  }
}

10. v-auto-height 自适应高度(表格/弹窗常用)

自动计算高度,避免滚动条错乱

// directives/autoHeight.js
export default {
  mounted(el) {
    const resize = () => {
      const top = el.getBoundingClientRect().top
      el.style.height = window.innerHeight - top - 20 + 'px'
    }
    resize()
    window.addEventListener('resize', resize)
    el._resize = resize
  },
  unmounted(el) {
    window.removeEventListener('resize', el._resize)
  }
}

统一注册(Vue3)

directives/index.js 统一导出:

import permission from './permission'
import debounce from './debounce'
// ...其他

export default {
  install(app) {
    app.directive('permission', permission)
    app.directive('debounce', debounce)
  }
}

main.js 引入:

import directives from '@/directives'
app.use(directives)

到此这篇关于10个Vue项目必备的高频实用自定义指令(复制即用)的文章就介绍到这了,更多相关Vue自定义指令内容请搜索脚本之家以前的文章或继续浏览下面的相关文章希望大家以后多多支持脚本之家!

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