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背景

给视频和文档的div区域增加水印。以下代码可以在任意位置增加水印。

js代码实现

var now = getNow();watermark({"watermark_txt":"A B C X Y Z "+now});function watermark(settings) {	//此处可以更改自己想要初始化的id。	var ele = document.getElementById("myBody");    //默认设置    var defaultSettings = {        watermark_txt: "text",        watermark_x: 20, //水印起始位置x轴坐标        watermark_y: 20, //水印起始位置Y轴坐标        watermark_rows: 20, //水印行数        watermark_cols: 20, //水印列数        watermark_x_space: 100, //水印x轴间隔        watermark_y_space: 50, //水印y轴间隔        watermark_color: '#aaa', //水印字体颜色        watermark_alpha: 0.4, //水印透明度        watermark_fontsize: '15px', //水印字体大小        watermark_font: '微软雅黑', //水印字体        watermark_width: 210, //水印宽度        watermark_height: 80, //水印长度        watermark_angle: 20 //水印倾斜度数    };    if (arguments.length === 1 && typeof arguments[0] === "object") {        var src = arguments[0] || {};        for (key in src) {            if (src[key] && defaultSettings[key] && src[key] === defaultSettings[key]) continue;            else if (src[key]) defaultSettings[key] = src[key];        }    }    var oTemp = document.createDocumentFragment();    //获取页面最大宽度    var page_width = Math.max(ele.scrollWidth, ele.clientWidth);    var cutWidth = page_width * 0.0150;    var page_width = page_width - cutWidth;    //获取页面最大高度    var page_height = Math.max(ele.scrollHeight, ele.clientHeight) ;    //如果将水印列数设置为0，或水印列数设置过大，超过页面最大宽度，则重新计算水印列数和水印x轴间隔    if (defaultSettings.watermark_cols == 0 || (parseInt(defaultSettings.watermark_x + defaultSettings.watermark_width * defaultSettings.watermark_cols + defaultSettings.watermark_x_space * (defaultSettings.watermark_cols - 1)) > page_width)) {        defaultSettings.watermark_cols = parseInt((page_width - defaultSettings.watermark_x + defaultSettings.watermark_x_space) / (defaultSettings.watermark_width + defaultSettings.watermark_x_space));        defaultSettings.watermark_x_space = parseInt((page_width - defaultSettings.watermark_x - defaultSettings.watermark_width * defaultSettings.watermark_cols) / (defaultSettings.watermark_cols - 1));    }    //如果将水印行数设置为0，或水印行数设置过大，超过页面最大长度，则重新计算水印行数和水印y轴间隔    if (defaultSettings.watermark_rows == 0 || (parseInt(defaultSettings.watermark_y + defaultSettings.watermark_height * defaultSettings.watermark_rows + defaultSettings.watermark_y_space * (defaultSettings.watermark_rows - 1)) > page_height)) {        defaultSettings.watermark_rows = parseInt((defaultSettings.watermark_y_space + page_height - defaultSettings.watermark_y) / (defaultSettings.watermark_height + defaultSettings.watermark_y_space));        defaultSettings.watermark_y_space = parseInt(((page_height - defaultSettings.watermark_y) - defaultSettings.watermark_height * defaultSettings.watermark_rows) / (defaultSettings.watermark_rows - 1));    }    var x;    var y;    for (var i = 0; i < defaultSettings.watermark_rows; i++) {        y = defaultSettings.watermark_y + (defaultSettings.watermark_y_space + defaultSettings.watermark_height) * i;        for (var j = 0; j < defaultSettings.watermark_cols; j++) {            x = defaultSettings.watermark_x + (defaultSettings.watermark_width + defaultSettings.watermark_x_space) * j;            var mask_div = document.createElement('div');            mask_div.id = 'mask_div' + i + j;            mask_div.className = 'mask_div';            mask_div.appendChild(document.createTextNode(defaultSettings.watermark_txt));            //设置水印div倾斜显示            mask_div.style.webkitTransform = "rotate(-" + defaultSettings.watermark_angle + "deg)";            mask_div.style.MozTransform = "rotate(-" + defaultSettings.watermark_angle + "deg)";            mask_div.style.msTransform = "rotate(-" + defaultSettings.watermark_angle + "deg)";            mask_div.style.OTransform = "rotate(-" + defaultSettings.watermark_angle + "deg)";            mask_div.style.transform = "rotate(-" + defaultSettings.watermark_angle + "deg)";            mask_div.style.visibility = "";            mask_div.style.position = "absolute";            mask_div.style.left = x + 'px';            mask_div.style.top = y + 'px';            mask_div.style.overflow = "hidden";            mask_div.style.zIndex = "9999";            //让水印不遮挡页面的点击事件            mask_div.style.pointerEvents = 'none';            mask_div.style.opacity = defaultSettings.watermark_alpha;            mask_div.style.fontSize = defaultSettings.watermark_fontsize;            mask_div.style.fontFamily = defaultSettings.watermark_font;            mask_div.style.color = defaultSettings.watermark_color;            mask_div.style.textAlign = "center";            mask_div.style.width = defaultSettings.watermark_width + 'px';            mask_div.style.height = defaultSettings.watermark_height + 'px';            mask_div.style.display = "block";            oTemp.appendChild(mask_div);        };    };    ele.appendChild(oTemp);}function getNow() {    var d = new Date();    var year = d.getFullYear();    var month = change(d.getMonth() + 1);    var day = change(d.getDate());    var hour = change(d.getHours());    var minute = change(d.getMinutes());    var second = change(d.getSeconds());    function change(t) {        if (t < 10) {            return "0" + t;        } else {            return t;        }    }    var time = year + '年' + month + '月' + day + '日 ' + hour + '时' + minute + '分' + second + '秒';    return time;}