javaScript写水印js过程中window对象的属性丢失问题

/** *  * * @author       caiwei * @version      1.0 * @created      2017-09-21 16:12:06 * @since        1.0 **/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: '#000000',//水印字体颜色        watermark_alpha: 0.3,//水印透明度        watermark_fontsize: '18px',//水印字体大小        watermark_font: '微软雅黑',//水印字体        watermark_width: 120,//水印宽度        watermark_height: 80,//水印长度        watermark_angle: 15//水印倾斜度数    };    //采用配置项替换默认值，作用类似jquery.extend    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);    //获取页面最大长度    var page_height = Math.max(document.body.scrollHeight, document.body.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.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";            //mask_div.style.border="solid #eee 1px";            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);}watermark({watermark_txt: "测试水印"});//传入动态水印内容//onload时触发水印绘制window.onload = function () {    watermark({watermark_txt: "测试水印"});};//onresize时触发水印绘制window.onresize = function () {    watermark({watermark_txt: "测试水印", watermark_width: 50})};var watermarkStr = window.parent.watermarkStr;//这里的父窗口的watermarkStr是字符串，在var watermarkStr 时虽然时全局变量但是并未赋值，所以需要重新赋值if (!watermarkStr) {//可以ajax请求后端获取水印信息    $.ajax({        type: 'get',        url: 'api/v1/system/sysInfo',        data: 'json'    }).then(function (res) {        if (res.meta.status == 0 && res.data.waterFlag == 1) {            watermarkStr = res.data;//水印信息        } else {            watermarkStr = 'closed';        }    });    if (watermarkStr != 'closed') {        setTimeout(function () {        //间隔两秒填充水印            watermark({watermark_txt: watermarkStr});        }, 2000);    }}window.parent.watermarkStr = watermarkStr;//此处很重要，否则在页面嵌入iframe时，iframe的window.parent取不到watermarkStr// 注意：JavaScript中对象属性var 声明的全局属性也即是window的属性，在requirejs中 window.parent.watermarkStr = watermarkStr;这个代码 若没有window.parent取不到watermarkStr属性