vue自动生成二维码并下载打印到本地

1、安装

npm i vue-qriously -S

2、引入，main.js文件

// 二维码
import VueQriously from 'vue-qriously'
Vue.use(VueQriously)

3、使用

<Button type="info" @click="scan">查看</Button>

<Button type="info" @click="download">下载</Button>

<!-- 二维码 -->
<Modal v-model="isShowQrcode" :closable="false"  width="232" :footer-hide="true">
  <qriously id="qrcode" :value="qrcode_url" :size="200" /> 
　<p style="textAlign:center;">请使用微信扫一扫</p> 
</Modal>

<script>
    data() {
        return {
          isShowQrcode:false,//二维码弹窗
          qrcode_url:"",//二维码显示内容
        }
      },
    methods:{
        // 查看二维码
        scan(){
          this.isShowQrcode = true;//打开二维码弹窗
          this.qrcode_url = "二维码需要显示的内容";
        },

        // 下载二维码
        download() {
          this.qrcode_url = "";
          this.qrcode_url = "维码需要显示的内容";

          // 先找到canvas节点下的二维码图片
          let myCanvas = document.getElementById("qrcode").getElementsByTagName("canvas");
          // 创建一个a节点
          let a = document.createElement("a");
          // 设置a的href属性将canvas变成png格式
          let imgURL = myCanvas[0].toDataURL("image/jpg");
          let ua = navigator.userAgent;
          if (ua.indexOf("Trident") != -1 && ua.indexOf("Windows") != -1) {
            // IE内核 并且  windows系统 情况下 才执行;
            var bstr = atob(imgURL.split(",")[1]);
            var n = bstr.length;
            var u8arr = new Uint8Array(n);
            while (n--) {
              u8arr[n] = bstr.charCodeAt(n);
            }
            var blob = new Blob([u8arr]);
            window.navigator.msSaveOrOpenBlob(blob, "download" + "." + "png");
          } else if (ua.indexOf("Firefox") > -1) {
            //火狐兼容下载
            let blob = this.base64ToBlob(imgURL); //new Blob([content]);
            let evt = document.createEvent("HTMLEvents");
            evt.initEvent("click", true, true); //initEvent 不加后两个参数在FF下会报错  事件类型，是否冒泡，是否阻止浏览器的默认行为
            a.download = " "; //下载图片名称，如果填内容识别不到，下载为未知文件，所以我这里就不填为空
            a.href = URL.createObjectURL(blob);
            a.dispatchEvent(
              new MouseEvent("click", {
                bubbles: true,
                cancelable: true,
                view: window,
              })
            ); //兼容火狐
          } else {
            //谷歌兼容下载
            // a.href = myCanvas[0].toDataURL('image/png').replace('image/png', 'image/octet-stream')
            a.href = myCanvas[0].toDataURL("image/jpg");
            //设置下载文件的名字
            a.download = "download";
            //点击
            a.click();
          }
        },

        //base64转blob
        base64ToBlob(code) {
          let parts = code.split(";base64,");
          let contentType = parts[0].split(":")[1];
          let raw = window.atob(parts[1]);
          let rawLength = raw.length;
          let uInt8Array = new Uint8Array(rawLength);
          for (let i = 0; i < rawLength; ++i) {
            uInt8Array[i] = raw.charCodeAt(i);
          }
          return new Blob([uInt8Array], { type: contentType });
        }
    }
</script>