jquery动态更改svg image xlink：href

我试图用不是填充颜色的图像动态地更改多边形的填充.为此,我找到了一种将填充更改为图像的方法,但是我无法将xlink：href URL动态更改为随机URl.
有什么想法吗？谢谢你的帮助！

<svg xmlns="@R_673_10107@://www.w3.org/2000/svg" xmlns:xlink="@R_673_10107@://www.w3.org/1999/xlink" version="1.1" x="0px" y="0px" width="320px" height="480px" viewBox="0 0 320 480" enable-BACkground="new 0 0 320 480" xml:space="preserve" xmlns:xml="@R_673_10107@://www.w3.org/XML/1998/namespace">
<pattern patternUnits="userSpaceOnUse" id="pat1" x="10" y="10" 
 width="425" height="319">
    <image id="BACkground" width="100%" height="100%" 
     xlink:href="@R_673_10107@://www.w3.org/1999/xlink" />
</pattern>
<g id="Layer_1">
    <polygon class="BACkground"  fill="url(#pat1)" points="265.188,329.922 160.198,358 55.208,329.922 55.208,120.868 265.188,120.868  "/>

</g>
<g id="Layer_2">
    <g id="brand_mark_1_">
        <g>
            <rect x="265.188" y="120.868" fill="#FFFFFF" width="23.812" height="44.378"/>
            <g>
                <path fill="#020304" d="M275.372,149.035c0,0.949,0.77,1.72,1.721,1.72c0.949,1.72-0.771,1.72-1.72      c0-0.023-0.003-0.044-0.004-0.066v-16.261c0.004-0.043,0.007-0.088,0.007-0.134c0-0.95-0.77-1.72-1.719-1.72      c-0.942,0-1.707,0.757-1.72,1.695h-0.005v16.461h0.001C275.374,149.017,275.372,149.025,149.035z"/>
                <circle fill="#F5170D" cx="277.093" cy="153.541" r="1.72"/>
            </g>
        </g>
    </g>
</g>
</svg>


 $(document).ready(function() {
                var randomColor = Math.floor(Math.random()*16777215).toString(16),randomnumber = Math.floor((Math.random()*855)+48),BACkg = $('#BACkground');
                    $("body").css("BACkground-color",randomColor);
                    BACkg.attr("@R_673_10107@://www.w3.org/1999/xlink","xlink:href","url(@R_673_10107@://blob.apliiq.com/sitestorage/fabric/" + randomnumber + ".png)");
                    $('a#cta').attr("href","/designyourown/?fabricID=" + randomnumber );               
            });

$(document).ready(function () {
    var randomColor = Math.floor(Math.random() * 16777215).toString(16),randomnumber = Math.floor((Math.random() * 855) + 48),BACkg = $('#BACkground');
    $("body").css("BACkground-color",'#' + randomColor);
    BACkg.attr("xlink:href","@R_673_10107@://blob.apliiq.com/sitestorage/fabric/" + randomnumber + ".png");
    $('a#cta').attr("href","/designyourown/?fabricID=" + randomnumber);
});