实现效果：（左边横屏，右边竖屏）

前言：【使用开源项目smooth-signature 实现签名的功能。Gitee 地址是 ：GitHub - linjc/smooth-signature: H5带笔锋手写签名，支持PC端和移动端，任何前端框架均可使用

以下代码可复制粘贴直接用，改下文件路径即可】

1.在项目中安装依赖包：npm install --save smooth-signature

2.我是放到一个dialog里，可根据需求自行开发。

弹框代码：

 <!--签名-->
  <Dialog
    v-model="signatureVisible"
    title="电子签名"
    width="100%"
    destroy-on-close
    draggable
    :append-to-body="true"
    @close="handleClose"
  >
    <div v-loading="endLoading">
      <ESign @closeson="closeVisi" />
    </div>
    <button v-show="false" @click="closeVisi">关闭</button>
  </Dialog>

引入模块：

import ESign from '@/views/officeDocument/office/components/packages/ESign/src/index2.vue'

使用方法：

//电子签名
const signatureVisible = ref(false)
const signatureBtn = () => {
  signatureVisible.value = true
}
//子组件关闭调用此方法
const closeVisi = () => {
  signatureVisible.value = false
}

2.开发电子签名功能及样式

电子签名文件目录（src/index.vue省略，主要是index2.vue文件)：

packages/index.ts文件代码：

import { App, Plugin } from 'vue'

import { ESignPlugin } from './ESign'
const XiPlugin: Plugin = {
  install(app: App) {
    ESignPlugin.install?.(app)
  }
}

export default XiPlugin

export * from './ESign'

packages/Esign/index.ts文件代码：

import { App, Plugin } from 'vue'
import ESign from './src/index.vue'

export const ESignPlugin: Plugin = {
  install(app: App) {
    app.component('ESign', ESign)
  }
}

export { ESign }

 packages/Edign/src/index2.vue文件代码（主要代码）：

<template>
  <div class="sign-finish">
    <div class="wrap1" v-show="showFull">
      <span class="sign-title">请在区域内签字</span>
      <canvas class="canvas1" ref="canvas1"></canvas>
      <div class="actions">
        <button class="danger" @click="handleClear1">清除</button>
        <button class="warning" @click="handleUndo1">撤销</button>
        <button class="primary" @click="handleFull">横屏</button>
        <button class="success" @click="handlePreview1">保存</button>
      </div>
    </div>
    <div class="wrap2" v-show="!showFull">
      <div class="actionsWrap">
        <div class="actions">
          <button class="danger" @click="handleClear2">清除</button>
          <button class="warning" @click="handleUndo2">撤销</button>
          <button class="primary" @click="handleFull">竖屏</button>
          <button class="success" @click="handlePreview2">保存</button>
        </div>
      </div>
      <canvas class="canvas" ref="canvas2"></canvas>
    </div>
  </div>
</template>

<script lang="ts" setup>
import { emit } from 'process'
import { ref, watch, onMounted, onUnmounted } from 'vue'
import SmoothSignature from 'smooth-signature'

//组件电子签名
const canvas = document.querySelector('canvas')
// const signature = new SmoothSignature(canvas)
const showFull = ref(true)
const canvas2 = ref<any>(null)
const canvas1 = ref<any>(null)
const signature1 = ref<any>(null)
const signature2 = ref<any>(null)
const emit = defineEmits(['closeson'])

//坚屏横屏
const handleFull = () => {
  showFull.value = !showFull.value
}
const initSignature1 = () => {
  // const canvas = this.$refs["canvas1"]
  const canvas = canvas1.value as any
  const options = {
    width: window.innerWidth - 30,
    height: 200,
    minWidth: 2,
    maxWidth: 6,
    openSmooth: true,
    // color: "#1890ff",
    bgColor: '#f6f6f6'
  }
  signature1.value = new SmoothSignature(canvas, options)
}
const initSignture2 = () => {
  // const canvas = this.$refs["canvas2"]
  const canvas = canvas2.value as any
  const options = {
    width: window.innerWidth - 120,
    height: window.innerHeight - 80,
    minWidth: 3,
    maxWidth: 10,
    openSmooth: true,
    // color: "#1890ff",
    bgColor: '#f6f6f6'
  }
  signature2.value = new SmoothSignature(canvas, options)
}

const handleClear1 = () => {
  const sgn = signature1.value
  sgn.clear()
}
const handleClear2 = () => {
  const sgn2 = signature2.value
  sgn2.clear()
}
const handleUndo1 = () => {
  const sgn = signature1.value
  sgn.undo()
}
const handleUndo2 = () => {
  const sgn2 = signature2.value
  sgn2.undo()
}
const handlePreview1 = () => {
  const sgn = signature1.value
  const isEmpty = sgn.isEmpty()
  if (isEmpty) {
    alert('isEmpty')
    return
  }
  // const pngUrl = sgn.getPNG()
  const pngUrl = sgn.getJPG()
  console.log(pngUrl)
  emit('closeson')
  // window.previewImage(pngUrl);
}
const handlePreview2 = () => {
  const sgn2 = signature2.value
  const isEmpty = sgn2.isEmpty()
  if (isEmpty) {
    alert('isEmpty')
    return
  }
  const canvas = sgn2.getRotateCanvas(-90)
  const pngUrl = canvas.toDataURL()
  console.log('pngUrl', pngUrl)
  // 生成JPG
  //signature.getJPG() // 或者 signature.toDataURL('image/jpeg')
}

onMounted(() => {
  initSignature1()
  initSignture2()
})

// onUnmounted(() => {
//   removeEventListener()
// })
</script>

<style scoped lang="less">
.sign-finish {
  height: 100vh;
  width: 100vw;
  button {
    height: 32px;
    padding: 0 8px;
    font-size: 12px;
    border-radius: 2px;
  }
  .danger {
    color: #fff;
    background: #ee0a24;
    border: 1px solid #ee0a24;
  }
  .warning {
    color: #fff;
    background: #ff976a;
    border: 1px solid #ff976a;
  }
  .primary {
    color: #fff;
    background: #1989fa;
    border: 1px solid #1989fa;
  }
  .success {
    color: #fff;
    background: #07c160;
    border: 1px solid #07c160;
  }
  canvas {
    border-radius: 10px;
    border: 2px dashed #ccc;
  }
  .wrap1 {
    height: 100%;
    width: 96%;
    margin: auto;
    margin-top: 100px;
    .actions {
      display: flex;
      justify-content: space-around;
    }
  }
  .wrap2 {
    padding: 15px;
    height: 100%;
    display: flex;
    justify-content: center;
    .actionsWrap {
      width: 50px;
      display: flex;
      justify-content: center;
      align-items: center;
    }
    .canvas {
      flex: 1;
    }
    .actions {
      margin-right: 10px;
      white-space: nowrap;
      transform: rotate(90deg);
      button {
        margin-right: 20px;
      }
    }
  }
}
</style>

最后就实现啦！本人因项目 使用比较复杂，可根据个人情况减少代码。参考前面的开源项目地址即可。