web_sh_audit/src/utils/watermark.js

/**
 * 水印添加方法
 */
/**
 * 水印添加方法
 */
let setWatermark = (str1, str2) => {
  let waterMarkId = "waterMark_123";
  //   let waterMarkId = "1.23452384164.123412415";
  if (document.getElementById(waterMarkId) !== null) {
    document.body.removeChild(document.getElementById(waterMarkId));
  }
  let can = document.createElement("canvas");
  // 设置canvas画布大小
  can.width = 390;
  can.height = 180;
  let cans = can.getContext("2d");
  //   水印旋转角度
  cans.rotate((-20 * Math.PI) / 180);
  cans.font = "20px Vedana";
  // cans.fillStyle = "#666666";
  cans.fillStyle = "#F0FFFF";
  cans.textAlign = "center";
  cans.textBaseline = "Middle";
  cans.fillText(str1, can.width / 2, can.height); // 水印在画布的位置x，y轴
  cans.fillText(str2, can.width / 2, can.height + 22);

  let div = document.createElement("div");
  div.id = waterMarkId;
  div.style.pointerEvents = "none";
  div.style.top = "60px";
  div.style.left = "0px";
  div.style.opacity = "0.32";
  div.style.position = "fixed";
  div.style.zIndex = "100000";
  div.style.width = document.documentElement.clientWidth + "px";
  div.style.height = document.documentElement.clientHeight + "px";
  // div.style.background = "rgba(255, 255, 255, 0.2)";
  div.style.background =
    "url(" + can.toDataURL("image/png") + ") left top repeat";
  document.body.appendChild(div);
  return waterMarkId;
};

// 添加水印方法
export const setWaterMark = (str1, str2) => {
  let waterMarkId = setWatermark(str1, str2);
  if (document.getElementById(waterMarkId) === null) {
    waterMarkId = setWatermark(str1, str2);
  }
};

// 移除水印方法
export const removeWatermark = () => {
  let waterMarkId = "1.23452384164.123412415";
  if (document.getElementById(waterMarkId) !== null) {
    document.body.removeChild(document.getElementById(waterMarkId));
  }
};