$("body").append('<canvas id="qrcanvas" style="display:none;"></canvas>')
     $("#imgexif_imgfile").change(function(e) {
         var file = e.target.files[0];
         if (window.FileReader) {
             var fr = new FileReader();
             fr.readAsDataURL(file);
             fr.onloadend = function(e) {
                 var base64Data = e.target.result;
                 base64ToqR(base64Data)
             }
         }
     })

     function base64ToqR(data) {
         var c = document.getElementById("qrcanvas");
         var ctx = c.getContext("2d");

         var img = new Image();
         img.src = data;
         img.onload = function() {
             $("#qrcanvas").attr("width", img.width)
             $("#qrcanvas").attr("height", img.height)
             ctx.drawImage(img, 0, 0, img.width, img.height);
             var imageData = ctx.getImageData(0, 0, img.width, img.height);
             const code = jsQR(imageData.data, imageData.width, imageData.height, {
                 inversionAttempts: "dontInvert",
             });
             if (code) {
                 showCode(code.data)
             } else {
                 layer.alert("识别错误,请上传正确的二维码")
             }
         };
     }

     function showCode(code) {
         $("#resultpanel").show();
         $("#result").show();
         $(".vtextarea").val(code)
     }