给WordPress设置随机背景图片

在主题的header文件中，加入如下代码：

<?php
    $method = $_SERVER["REQUEST_SCHEME"];
    $images= [
        "://files.coderecord.cn/wpupload/2018/03/bg_boobs.png",
        "://files.coderecord.cn/wpupload/2018/03/bg_ants.png",
        "://files.coderecord.cn/wpupload/2018/03/bg_yourls.png"
    ];
     $random = rand(0,count($images) - 1);
     $url = $images[$random];
     echo '
        <style type="text/css" id="custom-background-css">
body.custom-background { background-image: url("'.$method.$url.'"); background-position: center center; background-size: auto; background-repeat: repeat; background-attachment: fixed; }
</style>
     ';
?>

$images是数组，可以修改为自己的图片