前段生成二维码下载，打印 QrCode

1. 首先引用js，一个是生成二维码一个是调用打印

2.直接上代码

<div class="container-div">
    <div id="qrcodeCanvas" ></div>
    <br>
    <a class="btn btn-success" onclick="downLoadImage()">
        <i class="fa fa-download"></i> <@ctx.i18n text = "下载"/>
    </a>
    <a class="btn btn-primary" onclick="printImage()">
        <i class="fa fa-print"></i> <@ctx.i18n text = "打印"/>
    </a>
</div>

<script type="text/javascript">
        var qrcdoe = "zzzzzz1231223";//需要生成二维码的文本
        let qrcodeCanvas = new QRCode(document.getElementById("qrcodeCanvas"),
            {
                text: qrcdoe,
                render: "canvas",
                width:350, //二维码的宽度
                height:350, //二维码的高度
                background:'#fff', //二维码的后景色
                foreground:'#000', //二维码的前景色
            });
        function downLoadImage()
        {
            var canvas = $("#qrcodeCanvas").find("canvas").get(0);
            var a = document.createElement("a");
            a.href = canvas.toDataURL();
            a.download = "采购订单"+".png";
            a.click();
        }
          function printImage()
          {
                   var img = document.getElementById("qrcodeCanvas");
                   var canvas  = $("#qrcodeCanvas").find("canvas").get(0);
                   img.src = canvas.toDataURL();
                  $("#qrcodeCanvas").jqprint({
                           debug:false,
                           importCSS:true,
                           printContainer:true,
                           operaSupport:false
                           });
          }
</script>