page({ // 繪製canvas drawCanvas:function(){ const ctx = wx.createCanvasContext('poster') // 畫圓形二維碼 this.circleImg(ctx,this.data.canvasLotteryQR, 151.5, 535.5, 36) // (canvas對象,二維碼圖片本地路徑(若是是網絡圖片先用wx.downloadFile存本地),座標x, 座標y, 半徑) }, // 圓形圖片 circleImg: function (ctx, img, x, y, r){ ctx.save() var d = 2 * r; var cx = x + r; var cy = y + r; ctx.arc(cx, cy, r, 0, 2 * Math.PI); ctx.clip(); ctx.drawImage(img, x, y, d, d); ctx.restore() },})