Vue和Canvas：如何实现手写签名和手势识别功能

<template>  <div>    <h1>手写签名</h1>    <canvas ref="canvas" @mousedown="startDrawing" @mousemove="drawing" @mouseup="stopDrawing"></canvas>    <button @click="clearCanvas">清除</button>    <button @click="saveSignature">保存</button>  </div></template><script>export default {  data() {    return {      isDrawing: false,      signatureData: null    }  },  methods: {    startDrawing(event) {      this.isDrawing = true;      const canvas = this.$refs.canvas;      const ctx = canvas.getContext('2d');      ctx.beginPath();      ctx.moveTo(event.pageX - canvas.offsetLeft, event.pageY - canvas.offsetTop);    },    drawing(event) {      if (!this.isDrawing) return;      const canvas = this.$refs.canvas;      const ctx = canvas.getContext('2d');      ctx.lineTo(event.pageX - canvas.offsetLeft, event.pageY - canvas.offsetTop);      ctx.stroke();    },    stopDrawing() {      this.isDrawing = false;    },    clearCanvas() {      const canvas = this.$refs.canvas;      const ctx = canvas.getContext('2d');      ctx.clearRect(0, 0, canvas.width, canvas.height);    },    saveSignature() {      const canvas = this.$refs.canvas;      this.signatureData = canvas.toDataURL();    }  }}</script><style scoped>canvas {  border: 1px solid black;}</style>

npm install hammerjs --save

<template>  <div>    <h1>手势识别</h1>    <canvas ref="canvas"></canvas>    <button @click="recognizeGesture">识别</button>  </div></template><script>import Hammer from 'hammerjs';export default {  mounted() {    const canvas = this.$refs.canvas;    const ctx = canvas.getContext('2d');    const mc = new Hammer(canvas);    mc.get('swipe').set({ direction: Hammer.DIRECTION_ALL });    mc.on('swiperight swipeleft swipeup swipedown', function (event) {      ctx.clearRect(0, 0, canvas.width, canvas.height);      ctx.fillText(event.type, canvas.width / 2, canvas.height / 2);    });  }}</script><style scoped>canvas {  border: 1px solid black;}</style>