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JS generates QR code

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Release： 2018-03-17 09:46:07

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This time I will bring you JS to generate QR code. What are the precautions for JS to generate QR code? The following is a practical case, let’s take a look.

HTML code:

<img style="display: none" id="qrcode" data-width="100" data-height="100" data-url="https://www.baidu.com/">

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Related JS code:

/**
  * 生成二维码
  * data-width={宽度}
  * data-height={高度}
  * data-url={链接}
  * @param $ele
  */
 var generatorQRCODE = function ($ele) {
  $ele.hide();
  var params = $ele.data();
  if(!params['width'] || !params['height'] || !params['url']){
   console.log('生成二维码参数错误');
   return false;
  }
  var image = new Image();
  var imageUrl = "http://pan.baidu.com/share/qrcode?w=" + params['width'] + "&h=" + params['height'] + "&url=" + params['url'] + "";
  image.src = imageUrl;
  $ele.attr('src', imageUrl);
  $ele.show();
 };
 
 generatorQRCODE($("#qrcode"));

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Let me share with you other generated 2 QR code case:

Use jquery.qrcode to generate QR code

1. First, add the jquery library file and qrcode plug-in to the page

<script type="text/javascript" src="jquery.js"></script> 
<script type="text/javascript" src="jquery.qrcode.min.js"></script>

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2. Add the following code to the page where the QR code needs to be displayed:

<p id="code"></p>

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3. Call the qrcode plug-in. Supports two methods of canvas and table for image rendering

canvas method:

$('#code').qrcode("http://www.baidu.com"); //任意字符串

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table method:

$("#code").qrcode({ 
  render: "table", //table方式 
  width: 200, //宽度 
  height:200, //高度 
  text: "www.helloweba.com" //任意内容 
});

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4. If the generated QR code content contains text, you need to Convert the string to UTF-8

Define the conversion method:

function toUtf8(str) {  
  var out, i, len, c;  
  out = "";  
  len = str.length;  
  for(i = 0; i < len; i++) {  
    c = str.charCodeAt(i);  
    if ((c >= 0x0001) && (c <= 0x007F)) {  
      out += str.charAt(i);  
    } else if (c > 0x07FF) {  
      out += String.fromCharCode(0xE0 | ((c >> 12) & 0x0F));  
      out += String.fromCharCode(0x80 | ((c >> 6) & 0x3F));  
      out += String.fromCharCode(0x80 | ((c >> 0) & 0x3F));  
    } else {  
      out += String.fromCharCode(0xC0 | ((c >> 6) & 0x1F));  
      out += String.fromCharCode(0x80 | ((c >> 0) & 0x3F));  
    }  
  }  
  return out;  
}

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Call the conversion method when generating:

var str = toUtf8("字符串测试！"); 
$('#code').qrcode(str);

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2. Dynamically generate in the Vue-cli project 2 QR code

1. Introduce qrcode--------npm install qrcode

2. Introduce

import QRCode from 'qrcode'  //定义生成二维码组件

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3 in main.js. Use it when needed Introduce

import QRCode from 'qrcode'   //引入生成二维码组件

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into the component that generates the QR code. 4. Define the generated location in HTML and pay attention to adding the style

<template>
 <p id="query">
  <h1>二维码：</h1>
  <canvas id="canvas"></canvas>
 </p>
</template>

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#canvas{
  width: 80%!important;
  height: auto!important;
 }

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5. Define the method to generate the QR code in js and call

//动态生成二维码
  useqrcode(){    //生成的二维码内容，可以添加变量　　　　this.QueryDetail='http://www.kspxzx.com/#/guard'+"?unique_code="+this.QueryDetail;var canvas = document.getElementById('canvas')
    QRCode.toCanvas(canvas, this.QueryDetail, function (error) {
    if (error) console.error(error)
    console.log('success!');
    })
  }

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I believe you have mastered the method after reading the case in this article. For more exciting information, please pay attention to other related articles on the php Chinese website!