NodeJS background

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Background:
1.PHP
2.Java
3.Python

Advantages
1. Performance
2. JS station with easy front
3.NodeJS facilitate distal Learning

https://nodejs.org/en/

1. Switch drive letter E:
2. change the directory name directory cd
3. The program execution node xxx.js

const http = require('http');

http.createServer(function(req, res){
 // 前台响应
 res.write("dashucoding");
 res.end();
});

// 监听
// 端口
server.listen(123);

nodeJS-- server

http-- protocol
REQUEST request
response in response to

File operations: FS - File System
HTTP - module

Asynchronous vs Synchronous
Asynchronous - Multiple operations can be carried out at the same time, the previous operation did not finish up, can begin after a
sync - one at a time

const fs=require('fs');

// readFile(文件名，回调函数)
readFile(文件名, function (err, data){})
writeFile(文件名, 内容, function (err){})

oBtn.onclick=function (){
	alert('a');
};

alert('b');

const http=require('http');
const fs=require('fs');

var server=http.createServer(function (req, res){
  //req.url=>'/index.html'
  //读取=>'./www/index.html'
  //  './www'+req.url
  var file_name='./www'+req.url;

  fs.readFile(file_name, function (err, data){
    if(err){
      res.write('404');
    }else{
      res.write(data);
    }
    res.end();
  });
});

server.listen(8080);

const fs=require('fs');

//writeFile(文件名, 内容, 回调)
fs.writeFile("bbb.txt", "dda", function (err){
  console.log(err);
});

const fs=require('fs');

//readFile(文件名, 回调函数)
fs.readFile('aaa.txt', function (err, data){
  if(err){
    console.log('读取失败');
  }else{
    console.log(data.toString());
  }
});

//fs.writeFile

class buffer for storing a binary data buffer
settimeout is time to perform a function for designating a specific function, method designated after the current time from the number of milliseconds
performed cleartimeout function for canceling the function specified in the function settimeout

var http = require('http');
http.createServer(function(req,res){
res.writeHead(200, {'Content-Type':'text/html'});
res.write('<head><meta charset="utf-8"/></head>');
res.end('你好\n');
}).listen(1234,"127.0.0.1");

var http=require('http');

http.createServer(function(req,res){
// 回调函数中的代码
})

 //一行
    white-space: nowrap;
    text-overflow: ellipsis;
    overflow: hidden;
    word-break: break-all;
//两行
 text-overflow: -o-ellipsis-lastline;
  overflow: hidden;
  text-overflow: ellipsis;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  line-clamp: 2;
  -webkit-box-orient: vertical;

Simple small program to achieve double-click event

data = {
      tabBar: [],
      // recommendList: [],
      floorList: [],
      banners: [],
      currentIndex: 1,
      canGetCoupon: false,
      // 触摸开始时间
      touchStartTime: 0,
      // 触摸结束时间
      touchEndTime: 0,
      // 最后一次单击事件点击发生时间
      lastTapTime: 0
    }

getCoupon: function (e) {
        let that = this
        if (that.touchEndTime - that.touchStartTime < 350) {
          // 当前点击的时间
          let currentTime = e.timeStamp
          let lastTapTime = that.lastTapTime
          // 更新最后一次点击时间
          that.lastTapTime = currentTime
          // 如果两次点击时间在300毫秒内，则认为是双击事件
          if (currentTime - lastTapTime < 300) {
            // 成功触发双击事件时，取消单击事件的执行
            // clearTimeout(that.lastTapTimeoutFunc)
            getCoupon({}).then(res => {
              this.canGetCoupon = false
            })
            wx.showToast({
              title: '优惠券领取成功',
              duration: 3000
            })
          }
        }

doubleClick(e){
	//e.timeStamp：当前点击时的毫秒数；
	// this.touchStartTime： 储存上一次点击时的毫秒数，默认0
        if (e.timeStamp - this.touchStartTime  < 300){
            双击，进入
        }

        this.touchStartTime = e.timeStamp;
        单击
    }

/*
        if ((e.timeStamp - this.touchStartTime) < 100) {
          getCoupon({}).then(res => {
            this.canGetCoupon = false
          })
          wx.showToast({
            title: '领取成功',
            icon: 'none',
            duration: 3000
          })
        }
        this.touchStartTime = e.timeStamp
        */

  // 触摸开始时间
  touchStartTime: 0,
  // 触摸结束时间
  touchEndTime: 0,  
  // 最后一次单击事件点击发生时间
  lastTapTime: 0, 
  // 单击事件点击后要触发的函数
  lastTapTimeoutFunc: null,

  /// 双击
  doubleTap: function(e) {
    var that = this
    // 控制点击事件在350ms内触发，加这层判断是为了防止长按时会触发点击事件
    if (that.touchEndTime - that.touchStartTime < 350) {
      // 当前点击的时间
      var currentTime = e.timeStamp
      var lastTapTime = that.lastTapTime
      // 更新最后一次点击时间
      that.lastTapTime = currentTime
 
      // 如果两次点击时间在300毫秒内，则认为是双击事件
      if (currentTime - lastTapTime < 300) {
        console.log("double tap")
        // 成功触发双击事件时，取消单击事件的执行
        clearTimeout(that.lastTapTimeoutFunc);
        wx.showModal({
          title: '提示',
          content: '双击事件被触发',
          showCancel: false
        })
      }
    }
  },

Console, global scope, global variables and functions, events, and event handling mechanism ring mechanism, how to use the debugging tools provided in the framework node.js.

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