ASP.Net Core 文件上传进度会话

Question

我正在 ASP.Net Core 中编写文件上传，我正在尝试更新进度条，但是当从 javascript 调用 Progress 操作时，会话值未正确更新。

使用以下方法将进度保存在用户会话中：

public static void StoreInt(ISession session, string key, int value)
{
    session.SetInt32(key, value);
}

上传：

$.ajax(
  {
      url: "/Upload",
      data: formData,
      processData: false,
      contentType: false,
      type: "POST",
      success: function (data) {
          clearInterval(intervalId);
          $("#progress").hide();
          $("#upload-status").show();
      }
  }
);

获取进度值：

intervalId = setInterval(
  function () {
      $.post(
        "/Upload/Progress",
        function (progress) {
            $(".progress-bar").css("width", progress + "%").attr("aria-valuenow", progress);
            $(".progress-bar").html(progress + "%");
        }
      );
  },
  1000
);

上传动作：

[HttpPost]
public async Task<IActionResult> Index(IList<IFormFile> files)
{
    SetProgress(HttpContext.Session, 0);
    [...]

    foreach (IFormFile file in files)
    {
        [...]
        int progress = (int)((float)totalReadBytes / (float)totalBytes * 100.0);
        SetProgress(HttpContext.Session, progress);
        // GetProgress(HttpContext.Session) returns the correct value
    }

    return Content("success");
}

进展行动：

[HttpPost]
public ActionResult Progress()
{
    int progress = GetProgress(HttpContext.Session);
    // GetProgress doesn't return the correct value: 0 when uploading the first file, a random value (0-100) when uploading any other file

    return Content(progress.ToString());
}

Answer 1

好吧，我使用了@FarzinKanzi 建议的解决方案，它使用 XMLHttpRequest 处理进度客户端而不是服务器端：

$.ajax(
  {
      url: "/Upload",
      data: formData,
      processData: false,
      contentType: false,
      type: "POST",
      xhr: function () {
          var xhr = new window.XMLHttpRequest();
          xhr.upload.addEventListener("progress", function (evt) {
              if (evt.lengthComputable) {
                  var progress = Math.round((evt.loaded / evt.total) * 100);
                  $(".progress-bar").css("width", progress + "%").attr("aria-valuenow", progress);
                  $(".progress-bar").html(progress + "%");
              }
          }, false);
          return xhr;
      },
      success: function (data) {
          $("#progress").hide();
          $("#upload-status").show();
      }
  }
);

感谢您的帮助。