Vue3 QR code generation (succinct and clear)

1. Install the plug-in

npm install --save qrcode.vue

or

yarn add qrcode.vue

Second, introduce the plug-in to the page

import QrcodeVue from 'qrcode.vue'

Three, page realization

 <qrcode-vue :value="qrCode123" size:300  ></qrcode-vue>

:value="qrCode123" is the value in the QR code

Four, all code

<template>
  <el-button text @click="dialogVisible = true"
    >click to open the Dialog</el-button
  >

  <el-dialog
    v-model="dialogVisible"
    title="Tips"
    width="30%"
    :before-close="handleClose"
  >
     <qrcode-vue :value="qrCode123" size:300  ></qrcode-vue>
    <template #footer>
      <span class="dialog-footer">
        <el-button @click="dialogVisible = false">Cancel</el-button>
        <el-button type="primary" @click="dialogVisible = false"
          >Confirm</el-button
        >
      </span>
    </template>
  </el-dialog>
</template>

<script lang="ts" setup>
import { ref } from 'vue'
import { ElMessageBox } from 'element-plus'
import QrcodeVue from 'qrcode.vue'

const dialogVisible = ref(false)
const qrCode123 = ref("我是二维码信息")

const handleClose = (done: () => void) => {
  ElMessageBox.confirm('Are you sure to close this dialog?')
    .then(() => {
      done()
    })
    .catch(() => {
      // catch error
    })
}
</script>
<style scoped>
.dialog-footer button:first-child {
  margin-right: 10px;
}
</style>

Introduction to Vue3 (ignore)

What vue3.0 brings
1. Performance improvement,
package size reduced by 41%,
initial rendering is 55% faster, updated rendering block is 133%,
memory is reduced by 54%
......
2. Source code upgrade
uses Proxy instead of defineProperty to achieve Responsive
Rewrite the implementation of virtual DOM and Tree-Sharking
......
3. Embrace TypeScript
vue3.0 to better support TypeScript
4. The new feature
Composition API (combination api)

. setup configuration

. ref and reactive

。watch与watchEffect

. provide and inject

。 .......

new built-ins

。 Fragment

。Teleport

。Suspense

other changes

. new lifecycle hook

. The data option should always be declared as a function

. Remove keyCode support as v-on modifier