有些後端管理系統，因為業務邏輯的需要，需要加上水印，下面就是水印方法。

function watermark(settings) {
    debugger;
    //預設設定
    var defaultSettings={
        watermark_txt:"text",
        watermark_x:20,//水印起始位置x軸座標
        watermark_y:20,//水印起始位置Y軸座標
        watermark_rows:20,//水印行數
        watermark_cols:20,//水印列數
        watermark_x_space:100,//水印x軸間隔
        watermark_y_space:50,//水印y軸間隔
        watermark_color:'#aaa',//水印字型顏色
        watermark_alpha:0.4,//水印透明度
        watermark_fontsize:'15px',//水印字型大小
        watermark_font:'微軟雅黑',//水印字型
        watermark_width:210,//水印寬度
        watermark_height:80,//水印長度
        watermark_angle:15//水印傾斜度數
    };
    //採用配置項替換預設值，作用類似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();

    //獲取頁面最大寬度
    var page_width = Math.max(document.body.scrollWidth,document.body.clientWidth);
    var cutWidth = page_width*0.0150;
    var page_width=page_width-cutWidth;
    //獲取頁面最大高度
    var page_height = Math.max(document.body.scrollHeight,document.body.clientHeight)+450;
    // var page_height = document.body.scrollHeight+document.body.scrollTop;
    //如果將水印列數設定為0，或水印列數設定過大，超過頁面最大寬度，則重新計算水印列數和水印x軸間隔
    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));
    }
    //如果將水印行數設定為0，或水印行數設定過大，超過頁面最大長度，則重新計算水印行數和水印y軸間隔
    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));
            //設定水印div傾斜顯示
            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.pointerEvents='none';//pointer-events:none  讓水印不遮擋頁面的點選事件
            //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);
}
 

使用方法如下：

在需要加水印的頁面在初始方法中呼叫

最後所實現的效果如下

因為保密我就不截圖全屏了