let canvas = wx.createCanvasContext("shareCanvas");

//绘制背景

canvas.drawImage(res[1].path, 0, 0, 301, 420);

canvas.save();

//绘制二维码

canvas.drawImage(res[0].path, 108, 262, 85, 85);

//绘制文字

canvas.font = "normal bold 20px sans-serif";

canvas.fillStyle = "#fff";

canvas.setTextAlign("center");

canvas.fillText("您的好友“" + this.wechat + "”", 150, 40);

canvas.fillText("送你20元红包", 150, 65);

canvas.draw();