微信小程序实现预约生成二维码功能

<swiper  indicator-dots indicator-color="white" indicator-active-color="blue" 
 autoplay interval="2000" circular
>
<!-- 这部分是实现轮播图下面的小圆点，可以根据两个不同的属性来分别更改样式 -->
<swiper-item>
  <image src="/image/1606976870484.jpg"></image>
</swiper-item>
<swiper-item>
  <image src="/image/1606976921531.jpg"></image>
</swiper-item>
<swiper-item>
  <image src="/image/1606976936035.png"></image>
</swiper-item>
<swiper-item>
  <image src="/image/111.jpg"></image>
</swiper-item>
<swiper-item>
  <image src="/image/222.jpg"></image>
</swiper-item>
</swiper>
<button class="mybt" bindtap="yuyue">预约参观？</button>
<canvas type="2d"id="myQrcode"></canvas>

/* pages/youke/youke.wxss */
page{
    background-color:#f3ffff; 
   }
swiper{
    margin-top: 50rpx;
    width: 100%;
    height: 430rpx;
    border-radius: 30rpx;
}
swiper-item {
    width: 100%;
    height: 100%;
    border-radius: 50rpx;
  }
.mybt{
    margin-top: 100rpx;
    width:300rpx;
    background-color: rgb(41, 113, 248);
    color: rgb(255, 255, 255);
}
view{
    font-size: 45rpx;
    text-align: center;
    margin-top: 100rpx;
}
canvas{
    width: 230rpx;
    height: 230rpx;
    margin-top: 100rpx;
    margin-left: 260rpx;
}

import drawQrcode from '../../utils/weapp.qrcode.esm.js'

// pages/youke/youke.js
import drawQrcode from '../../utils/weapp.qrcode.esm.js'
Page({
    data: {
        yynum:500,
        randomNum:"0"
    },
    onLoad() {
    },
    onReady() {
    },
    onShow() {
    },
    onHide() {
    },
    onUnload() {
    },
    onPullDownRefresh() {
    },
    onReachBottom() {
    },
    onShareAppMessage() {
    },
    yuyue(msg){
        // console.log("lll")
        if(this.data.yynum>0&&this.data.randomNum=="0")
        {
            wx.showToast({
                icon: 'success',
                title: '预约成功~',
              })
             let y=this.data.yynum;
              y--;
              this.setData({
                yynum:y
              })
              let r=(Math.random()*1).toFixed(4)*10000
              this.setData({
                randomNum:r
              }),
              console.log(r);
              const query = wx.createSelectorQuery()
        query.select('#myQrcode')
            .fields({
                node: true,
                size: true
            })
            .exec((res) => {
                var canvas = res[0].node
                drawQrcode({
                    canvas: canvas,
                    canvasId: 'myQrcode',
                    width: 260,
                    padding: 30,
                    background: '#4169E1',
                    foreground: '#ffffff',
                    text: '个人二维码信息',
                })
                wx.canvasToTempFilePath({
                    canvasId: 'myQrcode',
                    canvas: canvas,
                    x: 0,
                    y: 0,
                    width: 260,
                    height: 260,
                    destWidth: 260,
                    destHeight: 260,
                })
            })
        }
        else if(this.data.randomNum!="0")
        {
            wx.showToast({
                icon: 'error',
                title: '禁止重复预约~',
              })
        }
        else{
            wx.showToast({
              icon: 'error',
              title: '很抱歉，已无预约名额~',
            })
        }
    }
})