modify：新增小程序

Sale/components/ec-canvas/wx-canvas.js

@@ -0,0 +1,61 @@
+export default class WxCanvas {
+  constructor(ctx, canvasId, isNew, canvasNode) {
+    this.ctx = ctx
+    this.canvasId = canvasId
+    this.chart = null
+    this.isNew = isNew
+
+    if (isNew) {
+      this.canvasNode = canvasNode
+    }
+
+    this.chart = null
+    this._init()
+  }
+
+  getContext(contextType) {
+    return this.ctx
+  }
+
+  setChart(chart) {
+    this.chart = chart
+  }
+
+  addEventListener() {
+    // 暂不支持事件监听
+  }
+
+  removeEventListener() {
+    // 暂不支持事件监听
+  }
+
+  _init() {
+    const dpr = wx.getSystemInfoSync().pixelRatio
+    this.ctx.scale(dpr, dpr)
+  }
+
+  // 代理 canvas 方法
+  setWidth(width) {
+    // Canvas 2D 不需要手动设置
+  }
+
+  setHeight(height) {
+    // Canvas 2D 不需要手动设置
+  }
+
+  getWidth() {
+    return this.canvasNode.width
+  }
+
+  getHeight() {
+    return this.canvasNode.height
+  }
+
+  addEvtListener() {
+    // 事件监听
+  }
+
+  removeEvtListener() {
+    // 移除监听
+  }
+}