1. 实现效果

2. vue3 注册全局自定义指令详解（v-copy）

1. 在src中，新建 directive 文件夹，在次新建 clipboard 文件夹（copy指令），创建 index.js 书写 copy指令方法

2. directive/clipboard/index.js clipboard（copy指令）完整代码

import Clipboard from 'clipboard'
if ( !Clipboard ) {
  throw new Error( '你须先运行 npm install `clipboard` --save ' )
}

export default {
  beforeMount( el, binding ) {
    if ( binding.arg === 'success' ) {
      el._v_clipboard_success = binding.value
    } else if ( binding.arg === 'error' ) {
      el._v_clipboard_error = binding.value
    } else {
      const clipboard = new Clipboard( el, {
        text() {
          return binding.value
        },
        action() {
          return binding.arg === 'cut' ? 'cut' : 'copy'
        }
      } )
      clipboard.on( 'success', e => {
        const callback = el._v_clipboard_success
        callback && callback( e )
      } )
      clipboard.on( 'error', e => {
        const callback = el._v_clipboard_error
        callback && callback( e )
      } )
      el._v_clipboard = clipboard
    }
  },
  beforeUpdate( el, binding ) {
    if ( binding.arg === 'success' ) {
      el._v_clipboard_success = binding.value
    } else if ( binding.arg === 'error' ) {
      el._v_clipboard_error = binding.value
    } else {
      el._v_clipboard.text = function() {
        return binding.value
      }
      el._v_clipboard.action = function() {
        return binding.arg === 'cut' ? 'cut' : 'copy'
      }
    }
  },
  unmounted( el, binding ) {
    if ( binding.arg === 'success' ) {
      delete el._v_clipboard_success
    } else if ( binding.arg === 'error' ) {
      delete el._v_clipboard_error
    } else {
      el._v_clipboard.destroy()
      delete el._v_clipboard
    }
  }
}

3. 在 directive 文件夹中新建 index.js，编写整合所有的自定义指令

import clipboard from './clipboard'
const directives = {
  clipboard
}

const registerDirective = app => {
  Object.keys( directives ).forEach( key => {
    app.directive( key, directives[key] )
  } )
}
export default registerDirective

3. main.js 注册全局自定义指令，挂载到 vue 上

// 自定义指令
import { createApp } from "vue";
import registerDirective from "@/directive";
const app = createApp(App);
const initApp = async () => {
  //  ....
  registerDirective(app);
  app.mount("#app");
};

initApp();

4. 页面使用

<template>
<el-row :gutter="10">
  <el-col :span="18">
    <el-input placeholder="请输入" v-model="value" />
  </el-col>
  <el-col :span="6">
    <el-button
      type="primary"
      v-clipboard:copy="value"
      v-clipboard:success="clipboardSuccess"
      v-clipboard:error="clipboardError"
    >
      复制
    </el-button>
  </el-col>
</el-row>
</template>

<script setup>
const value = ref('')

const clipboardSuccess = () => {
  ElMessage.success( '复制成功' )
}
const clipboardError = () => {
  ElMessage.error( '复制失败' )
}
</script>