项目中新建一个 watermark.js 文件

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
let watermark = {};

let setWatermark = (text, sourceBody) => {
  let id =
    Math.random() * 10000 +
    "-" +
    Math.random() * 10000 +
    "/" +
    Math.random() * 10000;

  if (document.getElementById(id) !== null) {
    document.body.removeChild(document.getElementById(id));
  }

  let can = document.createElement("canvas");
  can.width = 120; //设置水印之间的左右间距
  can.height = 80; //设置水印之间的上下间距

  let cans = can.getContext("2d");
  cans.rotate((-20 * Math.PI) / 180);
  cans.font = "15px Vedana";
  cans.fillStyle = "rgba(0, 0, 0, .5)";
  cans.textAlign = "left";
  cans.textBaseline = "Middle";
  cans.fillText(text, can.width / 20, can.height);

  let water_div = document.createElement("div");
  water_div.id = id;
  water_div.className = "watermarkClass";
  water_div.style.pointerEvents = "none";
  water_div.style.background =
    "url(" + can.toDataURL("image/png") + ") left top repeat";
  if (sourceBody) {
    water_div.style.width = "100%";
    water_div.style.height = "100%";
    sourceBody.appendChild(water_div);
  } else {
    water_div.style.top = "3px";
    water_div.style.left = "0px";
    water_div.style.position = "fixed";
    water_div.style.zIndex = "100000";
    water_div.style.width = document.documentElement.clientWidth + "px";
    water_div.style.height = document.documentElement.clientHeight + "px";
    document.body.appendChild(water_div);
  }

  return id;
};

/**
 *  该方法只允许调用一次
 *  @param:
 *  @text == 水印内容
 *  @sourceBody == 水印添加的位置，不传就是body
 * */
watermark.set = (text, sourceBody) => {
  const domArr = Array.from(document.getElementsByClassName("watermarkClass"));
  for (let i = 0; i < domArr.length; i++) {
    const element = domArr[i];
    // element.parentNode.removeChild(element);
    element.remove();
  }
  if (text == "") {
    return;
  }
  setWatermark(text, sourceBody);
  // let id = setWatermark(text, sourceBody);
  // setInterval(() => {
  //   if (document.getElementById(id) === null) {
  //     id = setWatermark(text, sourceBody);
  //   }
  // }, 2000);
  // window.onresize = () => {
  //   setWatermark(text, sourceBody);
  // };
};

export default watermark;

main.js 中引入 watermark.js

1
2
3
/ 引入水印文件地址
import watermark from './util/watermark.js'
Vue.prototype.$watermark = watermark

页面中使用

this.$watermark.set(text，dom)

参数 说明 是否必填
text 水印内容 是
dom 水印容器。若不传，则全屏水印，若传，则指定容器。 否

全屏水印

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
<template>
  <div class="page">
  </div>
</template>

<script>
export default {
  data() {
    return {};
  },
  mounted(){
    this.$watermark.set("水印")
  },
  beforeDestroy() {
    this.$watermark.set("");
  }
};
</script>

<style scoped>
.page{
  width: 100%;
  height: 100%;
  background-color: skyblue;
}
</style>

指定容器水印

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
<template>
  <div class="page">
    <div ref="content" style="width: 500px;height: 500px;border: 2px solid red;"></div>
  </div>
</template>

<script>
export default {
  data() {
    return {};
  },
  mounted(){
    this.$watermark.set("水印",this.$refs.content)
  },
  beforeDestroy() {
    this.$watermark.set("",this.$refs.content);
  }
};
</script>

<style scoped>
.page{
  width: 100%;
  height: 100%;
  background-color: skyblue;
}
</style>