进度图像上传Ajax jQuery

Question

我在FireFox中的ajax进度条有问题（在Chrome上工作正常）。如果我上传照片，他们会立即达到100％。

List[String] = List(Gateway = MSC050, Sequence = 176484,Gateway = MSC050, Sequence = 176485)

这是我在FireFox List[String] = List(50176484,50176485)

中的功能进度

$('.img_upload').on('change', function(e) {
  var file_data = $('.img_upload').prop('files')[0];
  var form_data = new FormData();
  form_data.append('file', file_data);
  $.ajax({
    url: "/admin/ajax/singleImg.php",
    dataType: 'text', // what to expect back from the PHP script, if anything
    cache: false,
    contentType: false,
    processData: false,
    data: form_data,
    type: 'post',
    xhr: function() {
      var myXhr = $.ajaxSettings.xhr();
      if (myXhr.upload) {
        $('.img_upload').parent().fadeOut();
        $('.progress').fadeIn();
        myXhr.upload.addEventListener('progress', progress, false);
      }
      return myXhr;
    },
    processData: false,
    contentType: false,
    success: function(data) {
      $('#nameImg').val(data);
    }
  });
});