我正在使用 Django 并嘗試使用 XMLHttpRequest 將網絡攝像頭數據發(fā)送到后臺 (view.py) 以處理每個幀。我點擊此鏈接，大多數人都為我的問題提出了類似的方法。$(document).ready(function(){  $('#trigger_button').click(function(){    navigator.mediaDevices.getUserMedia(constraints)    .then(stream => {      document.getElementById("myVideo").srcObject = stream;    })    .catch(err => {      alert('navigator.getUserMedia error: ', err)    });    drawCanvas.width = v.videoWidth;    drawCanvas.height = v.videoHeight;    imageCanvas.width = uploadWidth;    imageCanvas.height = uploadWidth * (v.videoHeight / v.videoWidth);    drawCtx.lineWidth = 4;    drawCtx.strokeStyle = "cyan";    drawCtx.font = "20px Verdana";    drawCtx.fillStyle = "cyan";    imageCanvas.getContext("2d").drawImage(v, 0, 0, v.videoWidth, v.videoHeight, 0, 0, uploadWidth, uploadWidth * (v.videoHeight / v.videoWidth));    imageCanvas.toBlob(postFile, 'image/jpeg');  });});function postFile(file) {  var formdata = new FormData();  formdata.append("image", file);  formdata.append("threshold", scoreThreshold);  var xhr = new XMLHttpRequest();  xhr.open('POST', apiServer, true);  xhr.onload = function () {    if (this.status === 200) {      var objects = JSON.parse(this.response);      drawBoxes(objects);      imageCtx.drawImage(v, 0, 0, v.videoWidth, v.videoHeight, 0, 0, uploadWidth, uploadWidth * (v.videoHeight / v.videoWidth));      imageCanvas.toBlob(postFile, 'image/jpeg');    }    else {      alert(this.status);    }  };  xhr.send(formdata);}然后，我嘗試訪問 view.py 中請求中的數據，如下所示：def control4(request):    print(request.POST.get('image'))    print(request.POST.get('threshold'))    return render(request, 'local.html')但是，雖然 request.Post.get('threshold') 返回一個值，但 request.POST.get('image') 返回 None 。另外，該方法重復3次后就停止發(fā)送反饋。我的意思是，control4 函數打印 3 次（我認為它應該一直工作到相機關閉為止）。誰能知道問題出在哪里嗎？