JS生成当前页面URL二维码

<script type='text/javascript' src='http://cdn.staticfile.org/jquery/2.1.1/jquery.min.js'></script> 
<script type="text/javascript" src="http://cdn.staticfile.org/jquery.qrcode/1.0/jquery.qrcode.min.js"></script>

<div id="qrcode"></div>
<a id="download" download="qrcode.jpg"></a> 
<button id="save">save</button>

<script>
    jQuery('#qrcode').qrcode({ width: 75, height: 75, text: window.location.href });
    $("#save").click(function () {
        var canvas = $('#qrcode').find("canvas").get(0);
        var url = canvas.toDataURL('image/jpeg');
        $("#download").attr('href', url).get(0).click();
        return false;
    });
</script>