Vue 实现电子签名并生成签名图片

1. 前言

电子签名在现代Web应用中越来越普遍，例如合同签署、确认表单等。本文将介绍如何使用Vue.js实现一个简单的电子签名功能，并将签名生成图片。

2. 项目结构

项目结构如下：

my-vue-signature/
├── public/
│   └── index.html
├── src/
│   ├── components/
│   │   └── SignaturePad.vue
│   ├── App.vue
│   ├── main.js
├── package.json
└── README.md

3. 代码实现

3.1 安装依赖

我们将使用一个轻量级的签名画布库 signature_pad，通过npm安装：
如果想学习signature_pad点击链接 - signature_pad 库详解

npm install signature_pad

3.2 创建签名画布组件

在 src/components 文件夹下创建 SignaturePad.vue 文件：

<template><div><canvas ref="signatureCanvas" @mousedown="startDrawing" @mousemove="draw" @mouseup="endDrawing" @mouseleave="endDrawing"></canvas><button @click="clearCanvas">清除</button><button @click="saveSignature">保存签名</button></div></template><script>import SignaturePad from 'signature_pad';export default {name: 'SignaturePad',data() {return {signaturePad: null,isDrawing: false,};},mounted() {const canvas = this.$refs.signatureCanvas;canvas.width = 600;canvas.height = 300;this.signaturePad = new SignaturePad(canvas);},methods: {startDrawing() {this.isDrawing = true;this.signaturePad.beginPath();},draw(event) {if (!this.isDrawing) return;const rect = this.$refs.signatureCanvas.getBoundingClientRect();this.signaturePad.lineTo(event.clientX - rect.left, event.clientY - rect.top);this.signaturePad.stroke();},endDrawing() {this.isDrawing = false;this.signaturePad.closePath();},clearCanvas() {this.signaturePad.clear();this.$emit('clean')},saveSignature() {if (this.signaturePad.isEmpty()) {alert('请先签名！');return;}const dataURL = this.signaturePad.toDataURL();this.$emit('save-signature', dataURL);},},};</script><style scoped>canvas {border: 1px solid #ccc;display: block;margin-bottom: 10px;}button {margin-right: 10px;}</style>

3.3 在 App.vue 中使用组件并生成签名图片

<template><div id="app"><div class="center"><h1>电子签名</h1><SignaturePad @save-signature="handleSaveSignature" @clean="handleClean" /><div ><h2>签名图片：</h2><div class="showimg"><img v-if="signatureImage" :src="signatureImage"  alt="Signature" /></div></div></div></div>
</template><script>
import SignaturePad from './components/SignaturePad.vue';export default {name: 'App',components: {SignaturePad,},data() {return {signatureImage: null,};},methods: {handleSaveSignature(dataURL) {this.signatureImage = dataURL;},handleClean(){this.signatureImage = null}},
};
</script><style>
#app {font-family: Avenir, Helvetica, Arial, sans-serif;text-align: center;margin-top: 60px;display: flex;justify-content: center;align-items: center;flex-direction: column
}
.center{}
.showimg{border-radius: 4px;border: 1px solid #ccc;padding: 10px;box-sizing: border-box;width: 610px;height: 310px;
}
</style>