html

<script src="https://cdn.staticfile.org/qrcodejs/1.0.0/qrcode.min.js"></script>
   <script src="qrcode.min.js"></script>
      
    <textarea type="text" placeholder="查找框" id="input1"></textarea>
    

    <textarea type="text" placeholder="替换框" id="input2"></textarea>

    <div id="qrcode"></div>

<button onclick="wifisc()">WIFI二维码生成</button>

JavaScript

function wifisc() { 
  var input1 = document.getElementById("input1").value; 
  var input = document.getElementById("input2").value;
    var qrcodeDiv = document.getElementById("qrcode");
  var content = `WIFI:S:${input1}\;T:WPA\;P:${input};H:true\;\;`;
  

  if (input == null || input.length == 0) {
  
  
  alert('请在“查找框”输入WIFI名称，“替换框”输入WIFI密码。');

  }else if(input1 == null || input1.length == 0){
  
    alert('请在“查找框”输入WIFI名称，“替换框”输入WIFI密码。');
  } else {
    

      
      var qrcode = new QRCode(qrcodeDiv, {
        text: content,
        width: 128,
        height: 128
      });
    



}};