新建JS文件

在 source 文件夹下新建 js 目录,并在里面新建 rphoto.js（确保没有与当前文件夹里的文件和主题相对应文件夹里面的文件名字冲突）
以下是 rphoto.js 的内容

function obcboPic() {
    var backPicture = document.getElementById("page-header");
    if (backPicture.style.backgroundImage == "") {
        var background_urls = [
            'https://s2.loli.net/2022/01/29/yX7lju25TbMVLnS.jpg',
            'https://s2.loli.net/2022/01/29/AyD3mTLvPa6YxN4.jpg',
            'https://s2.loli.net/2022/01/29/2ANgyCud5mf9SLX.jpg',
            'https://s2.loli.net/2022/01/29/ijTcD4sNQGtI7aO.jpg',
            'https://s2.loli.net/2022/01/29/lZfxzh2w83Y7UAH.jpg',
            'https://s2.loli.net/2022/01/29/7fWJp48Dm6kV3tA.jpg',
            'https://s2.loli.net/2022/01/29/Bt7njKX3pckosEA.jpg',
            'https://s2.loli.net/2022/01/29/YfIERQGwPyWpF95.jpg',
            'https://s2.loli.net/2022/01/29/oZUCqWKr2w1DO35.jpg',
            'https://s2.loli.net/2022/01/29/2n34ZH1LEsWgxJI.jpg',
            'https://s2.loli.net/2022/01/29/anU8Pp4syA1DfcJ.jpg',
            'https://s2.loli.net/2022/01/29/TbcZ3pC4ev7MBKS.jpg',
            'https://s2.loli.net/2022/01/29/WpYuKRmxjNkzt8a.jpg',
            'https://s2.loli.net/2022/01/29/PHR7bGNJgpS1xrB.jpg',
            'https://s2.loli.net/2022/01/29/eJqjtFW329GiLQD.jpg',
            'https://s2.loli.net/2022/01/29/MgK18FvA9rc7ipV.jpg',
            'https://s2.loli.net/2022/01/29/E4br3gUDTLVKp8o.jpg',
            'https://s2.loli.net/2022/01/29/WDzVHu9MgtC1fQ4.jpg',
            'https://s2.loli.net/2022/01/29/wPavu8hCZL5VXmN.jpg'
        ]
        var url = background_urls[Math.floor((Math.random() * background_urls.length))];
        var urlPhoto = ('background-image:url(' + url + ')');
        console.log("BackGround URL:" + url);
        backPicture.setAttribute("style", urlPhoto);
    }
}