为何我复制粘贴的开发文档代码都加载不出来我的飞机？只能显示矩形下落 我已经把图片放在跟game.js同一个目录下了，看到飞机只是闪了一下，就没了，矩形一直下落 const canvas = wx.createCanvas() const context = canvas.getContext('2d') // 创建一个 2d context context.fillStyle = '#1aad19' // 矩形颜色 // context.fillRect(0, 0, 100, 100) // 矩形左上角顶点为(0, 0)，右下角顶点为(100, 100) // context.fillRect(canvas.width / 2 - 50, 0, 100, 100) const { windowWidth, windowHeight } = wx.getSystemInfoSync() function drawRect(x, y) {   context.clearRect(0, 0, windowWidth, windowHeight)   context.fillRect(x, y, 100, 100) } drawRect(canvas.width / 2 - 50, 0) const rectX = canvas.width / 2 - 50 let rectY = 0 setInterval(function () {   drawRect(rectX, rectY++) }, 16) const image = wx.createImage() const imgX = canvas.width / 2 - 50 let imgY = 500 image.onload = function () {   context.drawImage(image, imgX, imgY)   } image.src = "../hero.png"