仅用canvas如何做地图呢？目前市面上流行的无非leaflet、openlayers、cesium等，但是归根到底都是基于canvas。本文仅做一个示例，仅利用canvas创建地图，流程如下：

1、依然是创建一个地图容器，canvas需要定义宽和高，单位像素。

<canvas id="mapCanvas" width="907" height="878"></canvas>

2、生成canvas地图

pageInit() { this.isMoving = false; this.scale = 1; this.originX = 0; this.originY = 0; this.startX = 0; this.startY = 0; const canvas = document.getElementById('mapCanvas'); const ctx = canvas.getContext('2d'); const img = new Image(); img.src = require('./img/map.png'); img.onload = () => { this.drawImage(ctx, img); }; }, drawImage(ctx, img) { ctx.clearRect(0, 0, ctx.canvas.width, ctx.canvas.height); ctx.save(); ctx.translate(this.originX, this.originY); ctx.scale(this.scale, this.scale); ctx.drawImage(img, 0, 50, img.width, img.height); this.drawMarkers(ctx); ctx.restore(); }, drawMarkers(ctx) { this.sourceList.forEach(item => { const markerImg = new Image(); markerImg.src = item.img; if (this.isMoving == true) { ctx.drawImage(markerImg, item.position[0], item.position[1], markerImg.width, markerImg.height); // 调整标记大小 } else { markerImg.onload = () => { ctx.drawImage(markerImg, item.position[0], item.position[1], markerImg.width, markerImg.height); // 调整标记大小 }; } }); },

3、由于是原始的canvas，在创建地图的时候需要自己定义地图的放大、缩小、拖、拉、拽、单击、双击、hover等鼠标事件。

addCanvasEventListeners() { const canvas = document.getElementById('mapCanvas'); canvas.addEventListener('wheel', this.handleWheel); canvas.addEventListener('mousedown', this.handleMouseDown); canvas.addEventListener('mousemove', this.handleMouseMove); canvas.addEventListener('mouseup', this.handleMouseUp); canvas.addEventListener('mouseout', this.handleMouseUp); canvas.addEventListener('click', this.handleClick); }, //鼠标滚轮，放大缩小 handleWheel(event) { this.detailShow = false; this.isMoving = true; event.preventDefault(); const canvas = document.getElementById('mapCanvas'); const ctx = canvas.getContext('2d'); const img = new Image(); img.src = require('./img/map.png'); img.onload = () => { const delta = event.deltaY > 0 ? -0.1 : 0.1; this.scale += delta; this.scale = Math.min(Math.max(0.5, this.scale), 3); // 限制缩放范围 this.drawImage(ctx, img); }; }, //鼠标按下 handleMouseDown(event) { this.isDragging = true; this.startX = event.clientX - this.originX; this.startY = event.clientY - this.originY; }, //鼠标移动 handleMouseMove(event) { this.detailShow = false; this.isMoving = true; if (this.isDragging) { const canvas = document.getElementById('mapCanvas'); const ctx = canvas.getContext('2d'); const img = new Image(); img.src = require('./img/map.png'); img.onload = () => { this.originX = event.clientX - this.startX; this.originY = event.clientY - this.startY; this.drawImage(ctx, img); } } }, //鼠标移动结束，抬起左键 handleMouseUp() { this.isDragging = false; }, //鼠标点击 handleClick(event) { },

效果如下：