给博客添加夜间护眼模式

进入主题，首先第一步，在您的页脚文件：footer.php上面加入以下js代码。

< script type = "text/javascript" >
    function switchNightMode() {
    var night = document.cookie.replace(/(?:(?:^|.*;\s*)night\s*\=\s*([^;]*).*$)|^.*$/, "$1") || "0";
    if (night == "0") {
        document.body.classList.add("night");
        document.cookie = "night=1;path=/";
        console.log("夜间模式开启")
    } else {
        document.body.classList.remove("night");
        document.cookie = "night=0;path=/";
        console.log("夜间模式关闭")
    }
    } (function() {
    if (document.cookie.replace(/(?:(?:^|.*;\s*)night\s*\=\s*([^;]*).*$)|^.*$/, "$1") === "") {
        if (new Date().getHours() > 21 || new Date().getHours() < 6) {
            document.body.classList.add("night");
            document.cookie = "night=1;path=/";
            console.log("夜间模式开启")
        } else {
            document.body.classList.remove("night");
            document.cookie = "night=0;path=/";
            console.log("夜间模式关闭")
        }
       } else {
        var night = document.cookie.replace(/(?:(?:^|.*;\s*)night\s*\=\s*([^;]*).*$)|^.*$/, "$1") || 
     "0";
        if (night == "0") {
            document.body.classList.remove("night")
        } else {
            if (night == "1") {
                document.body.classList.add("night")
            }
        }
      }
    })();
    </script>
< script type = "text/javascript" >
    function switchNightMode() {
    var night = document.cookie.replace(/(?:(?:^|.*;\s*)night\s*\=\s*([^;]*).*$)|^.*$/, "$1") || "0";
    if (night == "0") {
        document.body.classList.add("night");
        document.cookie = "night=1;path=/";
        console.log("夜间模式开启")
    } else {
        document.body.classList.remove("night");
        document.cookie = "night=0;path=/";
        console.log("夜间模式关闭")
    }
    } (function() {
    if (document.cookie.replace(/(?:(?:^|.*;\s*)night\s*\=\s*([^;]*).*$)|^.*$/, "$1") === "") {
        if (new Date().getHours() > 21 || new Date().getHours() < 6) {
            document.body.classList.add("night");
            document.cookie = "night=1;path=/";
            console.log("夜间模式开启")
        } else {
            document.body.classList.remove("night");
            document.cookie = "night=0;path=/";
            console.log("夜间模式关闭")
        }
       } else {
        var night = document.cookie.replace(/(?:(?:^|.*;\s*)night\s*\=\s*([^;]*).*$)|^.*$/, "$1") || 
     "0";
        if (night == "0") {
            document.body.classList.remove("night")
        } else {
            if (night == "1") {
                document.body.classList.add("night")
            }
        }
      }
    })();
    </script>
< script type = "text/javascript" >
    function switchNightMode() {
    var night = document.cookie.replace(/(?:(?:^|.*;\s*)night\s*\=\s*([^;]*).*$)|^.*$/, "$1") || "0";
    if (night == "0") {
        document.body.classList.add("night");
        document.cookie = "night=1;path=/";
        console.log("夜间模式开启")
    } else {
        document.body.classList.remove("night");
        document.cookie = "night=0;path=/";
        console.log("夜间模式关闭")
    }
    } (function() {
    if (document.cookie.replace(/(?:(?:^|.*;\s*)night\s*\=\s*([^;]*).*$)|^.*$/, "$1") === "") {
        if (new Date().getHours() > 21 || new Date().getHours() < 6) {
            document.body.classList.add("night");
            document.cookie = "night=1;path=/";
            console.log("夜间模式开启")
        } else {
            document.body.classList.remove("night");
            document.cookie = "night=0;path=/";
            console.log("夜间模式关闭")
        }
       } else {
        var night = document.cookie.replace(/(?:(?:^|.*;\s*)night\s*\=\s*([^;]*).*$)|^.*$/, "$1") || 
     "0";
        if (night == "0") {
            document.body.classList.remove("night")
        } else {
            if (night == "1") {
                document.body.classList.add("night")
            }
        }
      }
    })();
    </script>

加好后在您的页面body处加入php判断，这样当检测到cookie相关字段时直接输出body的class为night，已防止页面闪烁。在头部文件：header.php文件中加入以下代码

<body class="<?php echo($_COOKIE[night] == 1 ? night : ); ?>">
<body class="<?php echo($_COOKIE[night] == 1 ? night : ); ?>">
<body class="<?php echo($_COOKIE[night] == 1 ? night : ); ?>">

如果原中已有了class的话就将<?php echo($_COOKIE[night] == 1 ? night : ); ?>放在class=“”里面。

最后再将网站中所有需要变暗的地方调整其css，已达到变暗效果，具体css调整示例可看下方。

body.night 需要调整的区块{
    background-color: #000000;
    color: #aaa;
    }
    body.night img {
    filter: brightness(30%);
    }
body.night 需要调整的区块{
    background-color: #000000;
    color: #aaa;
    }
    body.night img {
    filter: brightness(30%);
    }
body.night 需要调整的区块{
    background-color: #000000;
    color: #aaa;
    }
    body.night img {
    filter: brightness(30%);
    }

由于每个网站或者博客CSS的命名不一样，所以请根据自己的网站/博客CSS进行修改，大家可以通过右键“审查元素”来获取CLASS的名字。

每个CLASS的区块都要用“body.night 需要调整的区块”书写，如“body.night h2”、“body.night .post-tags”等。

这样当晚上9点到白天6点之间，网站打开时就自动会变成暗黑模式。当然，你也可以加一个按钮，来手动控制打开关闭暗黑模式。如下代码。

<a href="javascript:switchNightMode()" target="_self">Dark</a>
<a href="javascript:switchNightMode()" target="_self">Dark</a>
<a href="javascript:switchNightMode()" target="_self">Dark</a>