【JavaScript】给页面加水印

        function watermark(settings) {
            //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(document.body.scrollWidth, document.body.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(document.body.scrollHeight, document.body.clientHeight) + 450;
            page_height = Math.max(page_height, window.innerHeight - 30);
            //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);
                };
            };
            document.body.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;
        }

使用方法：

var now = getNow();
watermark({ "watermark_txt": "小破孩的小站" + now });

var now = getNow();