// 获取二维码

  getscan: function (e) {

    var that = this;

    var userinfo = wx.getStorageSync('userinfo'); // 微信返回的用户信息

    var OpenId = userinfo.openId;

    var CodeCreateTime = util.formatTime(new Date()); // 当前生成二维码的时间

    console.log(CodeCreateTime)

    var text = OpenId + ';' + CodeCreateTime

    console.log('sssssss', text)

    that.setData({

      text: text

    })

    qrcode = new QRCode('canvas', {

      text: text,

      width: 155,

      height: 155,

      colorDark: "#000",

      colorLight: "#fff",

    });

    console.log('132', that.data.text)

    // 把canvase做成图片显示，就没有了层级问题

    // canvas 转图片的时候

    const ctx = wx.createCanvasContext('canvas')

    console.log(ctx)

    console.log(ctx.draw)

    ctx.draw(true, setTimeout(()=>{

      console.log('执行回调')

        wx.canvasToTempFilePath({

        x: 0,

        y: 0,

        width: 80,

        height: 80,

        canvasId: 'canvas',

        success: function (res) {

          console.log('wwweer', res)

          that.setData({

            radarImg: res.tempFilePath

          });

          console.log('147', that.data.text)

          console.log('325', that.data.radarImg)

        }

      });

  },300))

  },

wx.createCanvasContext 放在周期函数onshow里面就可以,但是点击事件不触发，不执行