打印JavaScript时未显示的QR代码

Question

我有一个Qr代码，我想打印。Qr代码在页面中显示得很好，但是当我试图打印它时，它并没有显示出来。

在主页上-

​

在印刷版上-

​

​

Html

<div class="container" id="printarea">
        <div class="card"style="height: 386px;">
          <div class="card-body">
            <center>
             <div id="qrcode"></div>
             <br>
              <br>
              <br>
              <br>
              <br>
              <br>
              <br>
            Powered by <img src="{{env('APP_URL')}}/public/{{$app_setting->webLogo}}" class="logo-icon" alt="logo icon" style="width:40px;">
            </center>
          </div>
        </div>
      </div>

JQuery Qr码

<script>
 var qrcode1 = "{{Auth::guard('vendor')->user()->VendorURL}}";
 jQuery(function(){
    jQuery('#qrcode').qrcode(qrcode1);
 })
</script>

Qr码打印码

function printFunc() {
var divToPrint = document.getElementById('printarea');
var htmlToPrint = '' +
    '<style type="text/css">' +
    'table th, table td {' +
    'border:1px solid #000;' +
    'padding;0.5em;' +
    '}' +
    '</style>';
htmlToPrint += divToPrint.innerHTML;
newWin = window.open("");
newWin.document.write("<h3 align='center'>QR Code</h3>");
newWin.document.write(htmlToPrint);
newWin.print();
newWin.close();

Answer 1

我得到了这个解决方案--将QR代码转换为图像

var canvas = $('#qrcode canvas');
var img = canvas.get(0).toDataURL("image/png");
newWin = window.open("");
var ig = '<p style="text-align: center;">Powered by <img src="{{env('APP_URL')}}/public/{{$app_setting->webLogo}}" class="logo-icon" alt="logo icon" style="width:40px;"></p>';
newWin.document.write("<h3 align='center'>QR Code</h3>");
newWin.document.write('<img style="display: block; margin: 0 auto;" src="'+img+'"/>');
newWin.document.write(ig);
setTimeout(function() {
newWin.print();
newWin.close();
}, 250);
}

Answer 2

只需在打印预览页面中启用背景图形，单击更多设置即可查看