Angular 生成页面水印

转载自：https://willern.gitee.io/2021/01/27/20210127/

1. 准备HTML代码

  

      

          {{item.txt}}
      
  

2. TS代码

// 页面水印
watermarkList = [];
watermark(settings) {
  //默认设置
  let 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: 150,//水印x轴间隔
    watermark_y_space: 100,//水印y轴间隔
    watermark_color: '#000000',//水印字体颜色
    watermark_alpha: 0.15,//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: 300,//水印宽度
    watermark_height: 100,//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 (let key in src) {
      if (src[key] && defaultSettings[key] && src[key] === defaultSettings[key])
        continue;
      else if (src[key])
        defaultSettings[key] = src[key];
    }
  }

  var resList = [];
  var page_width = document.body.offsetWidth;
  var page_height = document.body.offsetHeight;

  //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 ||  (defaultSettings.watermark_x + defaultSettings.watermark_width * defaultSettings.watermark_cols + defaultSettings.watermark_x_space * (defaultSettings.watermark_cols - 1) > page_width)) {
    defaultSettings.watermark_cols = (page_width - defaultSettings.watermark_x  + defaultSettings.watermark_x_space) / (defaultSettings.watermark_width + defaultSettings.watermark_x_space);
    defaultSettings.watermark_x_space = (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 ||
    (defaultSettings.watermark_y  + defaultSettings.watermark_height * defaultSettings.watermark_rows  + defaultSettings.watermark_y_space * (defaultSettings.watermark_rows - 1))  > page_height) {
    defaultSettings.watermark_rows =  (defaultSettings.watermark_y_space  + page_height - defaultSettings.watermark_y)  / (defaultSettings.watermark_height + defaultSettings.watermark_y_space);
    defaultSettings.watermark_y_space =  (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 = {
        style: "",
        txt: "",
      };

      mask_div.txt = defaultSettings.watermark_txt;
      //设置水印div倾斜显示
      mask_div.style = JSON.stringify({
        'pointer-events': 'none',
        '-webkit-transform': 'rotate(-' + defaultSettings.watermark_angle + 'deg)',
        '-moz-transform': 'rotate(-' + defaultSettings.watermark_angle + 'deg)',
        '-ms-transform': 'rotate(-' + defaultSettings.watermark_angle + 'deg)',
        '-o-transform': 'rotate(-' + defaultSettings.watermark_angle + 'deg)',
        'transform': 'rotate(-' + defaultSettings.watermark_angle + 'deg)',
        'position': 'absolute',
        'left': x + 'px',
        'top': y + 'px',
        'overflow': 'hidden',
        'z-index': '99999',
        'opacity': defaultSettings.watermark_alpha,
        'font-size': defaultSettings.watermark_fontsize,
        'font-family': defaultSettings.watermark_font,
        'color': defaultSettings.watermark_color,
        'text-align': 'center',
        'width': defaultSettings.watermark_width + 'px',
        'height': defaultSettings.watermark_height + 'px',
        'display': 'block',
      });

      resList = resList.concat(mask_div);
    }
  }
  return resList;
}

3. 页面初始化时调用方法

//初始化
    setTimeout(() => {
      setInterval(()=>{
        let text1 = { watermark_txt: 'Unapproved', watermark_fontsize: '16px'};
        this.watermarkList = this.watermark(text1);
        for(let item of this.watermarkList){
          let style = JSON.parse(item.style);
          // json字符串转换为json对象，因为ngStyle只支持对象
          item.objStyle = style;
        }
      },1000)
    }, 1000);

4. 效果

   
   
   image.png

亲测可用，可用参考实现
转载自：https://willern.gitee.io/2021/01/27/20210127/