HTML5网页水印SDK的实现方法

size: 字体大小color: 字体颜色id: canvasIdtext: 文本内容density: 间距clarity: 清晰度supportTip: Canvas不支持的文字提示

let body = document.getElementsByTagName('body');  let canvas = document.createElement('canvas');  canvas.style.cssText= 'position: fixed;width: 100%;height: 100%;left:0;top:0;z-index: -1;';  body[0].appendChild(canvas);

let canvas = document.getElementById(this.params.id);     let cxt = canvas.getContext(&#39;2d&#39;);     let times = window.screen.width * this.params.clarity / this.params.density;//横向文字填充次数     let heightTimes = window.screen.height * this.params.clarity * 1.5/ this.params.density; //纵向文字填充次数     cxt.rotate(-15*Math.PI/180); //倾斜画布        for(let i = 0; i < times; i++) {       for(let j = 0; j < heightTimes; j++) {         cxt.fillStyle = this.params.color;         cxt.font = this.params.size + &#39; Arial&#39;;         cxt.fillText(this.params.text, this.params.density*i, j*this.params.density);       }     }

let self = this;  window.setInterval(function(){  if (!document.getElementById(self.params.id)) {  self._init();  }  }, 1000);

var gulp = require('gulp'),      uglify = require("gulp-uglify"),      babel = require("gulp-babel");  gulp.task('minify', function () {      return gulp.src('./src/index.js') // 要压缩的js文件      .pipe(babel())      .pipe(uglify())      .pipe(gulp.dest('./dist')); //压缩后的路径  });