2017-03-01 86 views
0

Ciao我正在使用https://github.com/LazarSoft/jsqrcode,但我无法通过相机获取qrcode的解码。 我想要做的就是让阅读QR码的解码带lazarsoft的Qrcode阅读器

这是我的代码

HTML

<video autoplay></video> 
<canvas id="qr-canvas"></canvas> 

JS

 var video = document.querySelector('video'); 
     var constraints = 
     { 
      audio: false, 
      video: 
      { 
       facingMode: { exact: "environment" }, 
       width: { min: 100, ideal: 400, max: 450 }, 
       height: { min: 100, ideal: 400, max: 450 } 
      } 
     } 

     navigator.mediaDevices.getUserMedia(constraints) 
     .then(function(mediaStream) 
     { 

      video.srcObject = mediaStream; 
      video.onloadedmetadata = function(e) 
      { 
      video.play(); 
      }; 

     }).catch(function(err) 
     { 
      console.log(err.name + ": " + err.message); 
     }); 

     var qr_canvas = 
     document.getElementById('qr-canvas').getContext('2d'); 
     qr_canvas.drawImage(video, 0, 0, 400, 400); 
     qrcode.decode(); 


     function readQR(a) 
     { 
      alert(a); 
     } 

     qrcode.callback = readQR; 

古拉爵

回答