.page{
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
}

.confirmPsdText{
  font-weight: 10 !important;
}

.farther{
position:relative;
}

.child{
position:absolute;
bottom:0;
}

button[disabled]{
  background: rgb(126, 146, 137)!important;
  color: black!important;
}

box-shadow: 0 5px 10px rgba(0, 0, 0, 0.3);

switch (表达式) {
  case 变量:
    语句;
  case 数字:
    语句;
    break;
  case 字符串:
    语句;
    break;
  default:
    语句;
}

let mode=0;
console.log(`mode is ${mode}`);

let data={a:1,b:2};
let {c,d}=data;
console.log(c,d);

<view wx:for="{{show}}">
  <view>
    <text>{{item}}</text>
  </view>
<view>

  .publicitySwiper{
   height:100%;
   border-bottom: yellow 1px solid;
 }
 .publicitySwiper image{
   width: 100%;
   height: 98%;
 }

getWxInfo(e){
  let headImg = e.detail.userInfo.avatarUrl
}

<view wx:if="{{ !a }}">逻辑非</view>
<view wx:if="{{ a || b }}">逻辑或</view>
<view wx:if="{{ a && b }}">逻辑与</view>

<view wx:if="{{ a > 5 }}">6</view>
<view wx:elif="{{ a < 5 }}">4</view>
<view wx:else>5</view>

<view wx:for='{{dateArr}}'  class='{{item.isToday}}'></view>

<view wx:for='{{dateArr}}' key="*this"  class='{{item.isToday}}'></view>

<view data-date='19:30' ></view>

<!-- 基本用法 -->
<view class='{{(index == todayIndex) && isTodayWeek ? "weekMark" : ""}}'>
<!-- 多条件判断 -->
<view class='{{conId==0?'orange':(conId==1?'blue':'purple')}}'>

//将值赋值给上一页的data，相当于在上一页使用的this.setData
prevPage.setData({
  choice_time: dateList
})
//返回上一页
wx.navigateBack({
  delta: 1
})

let searchBar = this.selectComponent('#search-bar');//指向wxml文件中 自定义组件的id
searchBar.clearInput();//clearInput为自定义组件中的函数

<canvas canvas-id="canvas" style="width:{{cWidth}}px;height:{{cHeight}}px;position: absolute;left:-1000px;top:-1000px;"></canvas>

data: {
    cWidth: 0,
    cHeight : 0,
  },

wx.chooseImage({
      count: 1,
      sizeType: ['compressed'],
      sourceType: ['album'],
      success(res) {
        let imgurl = res.tempFilePaths[0]
        wx.getImageInfo({
          src: imgurl,
          success: function(res){
            //---------利用canvas压缩图片--------------
            var ratio = 2;
            var canvasWidth = res.width //图片原始长宽
            var canvasHeight = res.height
            while (canvasWidth > 400 || canvasHeight > 400){// 保证宽高在400以内
                canvasWidth = Math.trunc(res.width / ratio)
                canvasHeight = Math.trunc(res.height / ratio)
                ratio++;
            }
            that.setData({
                cWidth: canvasWidth,
                cHeight: canvasHeight
            })

            //----------绘制图形并取出图片路径--------------
            var ctx = wx.createCanvasContext('canvas')
            ctx.drawImage(res.path, 0, 0, canvasWidth, canvasHeight)
            ctx.draw(false, setTimeout(function(){
                 wx.canvasToTempFilePath({
                     canvasId: 'canvas',
                     destWidth: canvasWidth,
                     destHeight: canvasHeight,
                     success: function (res) {
                         let imgpath=res.tempFilePath //这里去除压缩后的图片
                         //..到此图片压缩结束,这里可添加转为base64的代码
                         //
                         //
                         //
                     },
                     fail: function (res) {
                         console.log(res.errMsg)
                    }
                })
            },100))    //留一定的时间绘制canvas


          }
        })
      }
    })

wx.getFileSystemManager().readFile({
  filePath: imgpath, //选择图片路径
  encoding: 'base64', //编码格式
  success: res => { //成功的回调
    console.log('data:image/png;base64,' + res.data)
    that.data.comEdit.comImg='data:image/png;base64,' + res.data
  }
})

npm install -save wx-server-sdk@latest

// 云函数入口文件
const cloud = require('wx-server-sdk')
cloud.init()
const db=cloud.database();
const _=db.command;
// 云函数入口函数
exports.main = async (event, context) => new Promise((resolve, reject) =>{
  
  // 在1.5 秒后返回结果给调用方（小程序 / 其他云函数）
  setTimeout(() => {
    resolve(returnInfo)//返回结果在前端的res.result里面
  }, 1500)
})

db.colletion(集合名).get().then(res=>{
  //....数据库调用成功的代码写这里
}).then(res=>{
  //....如果上一个then中的又调用了db数据库，并且成功了，后续代码可以写这里。.then可以循环叠加
}).cath(=>err{
  //....处理返回错误的结果
})

db.collection('Data_User').where({
        PHONE:"13962310765"
      }).get().then(res => {
        return res.data;
      })
//注意，数据在res的data集合中。

await db.collection("库名").add({
              data:{
                //....
              }
              }).then(res=>{
                //....
              })

@import '/miniprogram_npm/@vant/weapp/common/index.wxss';

<!-- html -->
<van-uploader file-list="{{ fileList }}" deletable="{{ true }}" max-count="{{3}}" 
bind:after-read="afterRead" bind:delete="imgdelte" />

data: {
  fileList:[]//子元素为字典形式的，格式为{url:"..."}
}，

  //图片选择后获取临时路径并上传
  afterRead(event) {
    const { file } = event.detail;
    console.log('获取临时文件 file:',file.url)
    // 当设置 mutiple 为 true 时, file 为数组格式，否则为对象格式
    this.data.fileList.push({url:file.url,deletable: true,})
    this.data.comEdit.img_num=this.data.fileList.length
    console.log(this.data.fileList)
    this.setData({
      fileList:this.data.fileList,
      comEdit: this.data.comEdit
    })
  },

 //------图片删除事件
  imgdelte(event){
    let index=event.detail.index
    this.data.fileList.splice(index,1)
    this.data.comEdit.img_num=this.data.fileList.length
    this.setData({
      fileList:this.data.fileList,
      comEdit: this.data.comEdit
    })
  },

npm install tencentcloud-sdk-nodejs --save