生成二维码和下载二维码

<div id="qrcode"></div>

<--这里引入的是我本地的-->
<script src="/static/libs/jquery/1.12.4/jquery.min.js" type="text/javascript" charset="utf-8"></script>
<script src="/static/admin/js/component/jquery.qrcode.min.js" type="text/javascript" charset="utf-8"></script>

methods:{
    // 生成二维码
    createQr(url) {
      $('#qrcode').qrcode({
        render: "canvas",
        width: 134,
        height: 134,
        // background: "#ffffff",       //二维码的后景色
        // foreground: "#3498db",       //二维码的前景色
        correctLevel: 2,
        text: url
      });
    },
    // 下载二维码
    downloadQr() {
      let oA = document.createElement("a");
      let canvas = $('#qrcode').find('canvas').get(0);
      oA.download = "二维码";
      oA.href = canvas.toDataURL("image/png");
      document.body.appendChild(oA);
      oA.click();
      oA.remove();
    },
    //$('#qrcode').empty()
}