Page({ onReady() { const query = wx.createSelectorQuery() query.select('#myCanvas') .fields({ node: true, size: true }) .exec((res) => { //console.log(res) 打印的为null const canvas = res[0].node const ctx = canvas.getContext('2d') const dpr = wx.getSystemInfoSync().pixelRatio canvas.width = res[0].width * dpr canvas.height = res[0].height * dpr ctx.scale(dpr, dpr) ctx.fillRect(0, 0, 100, 100) }) } }) [图片] [图片]