Writing server-side handler for jquery file upload

Question

I'm trying to get the blueimp jQuery-File-Upload component working in my MVC application.

Here's my code so far.

JavaScript:

$('#fileupload').fileupload({
    url: '@Url.Action("AddAttachment", "File")',
    dataType: 'json',
    progressall: function (e, data) {
        var progress = parseInt(data.loaded / data.total * 100, 10);
        console.log(progress);
    },
    add: function(e, data) {
        data.submit();
    },
    done: function (e, data) {
        $.each(data.result.files, function (index, file) {
            $('<p/>').text(file.name).appendTo(document.body);
        });
    }
});

Controller:

[HttpPost]
public JsonResult AddAttachment()
{
    var files = new List<FileAttachmentFileModel>();

    try
    {
        if (Request.Files.Count > 0)
        {
            using (var dbContext = new vegaEntities())
            using (var transaction = dbContext.Database.BeginTransaction())
            {
                for (int i = 0; i < Request.Files.Count; i++)
                {
                    HttpPostedFileBase file = Request.Files[i];

                    if (file.ContentLength > 0)
                    {
                        FileAttachment fileAttachment = new FileAttachment
                        {
                            Id = Guid.NewGuid(),
                            FileName = file.FileName,
                            ContentType = file.ContentType,
                            DateAdded = DateTime.UtcNow
                        };
                        // Load content
                        fileAttachment.Content = new byte[file.ContentLength];
                        file.InputStream.Read(fileAttachment.Content, 0, file.ContentLength);
                        // Add to database
                        dbContext.FileAttachments.Add(fileAttachment);
                        // Add to results
                        files.Add(new FileAttachmentFileModel
                        {
                            id = fileAttachment.Id.ToString(),
                            name = file.FileName,
                            size = file.ContentLength.FormatAsFileSize(),
                            //action = FileAttachmentFileModel.AddAction
                        });
                    }
                }
                dbContext.SaveChanges();
                transaction.Commit();
            }
        }
    }
    catch (Exception ex)
    {
        // TODO:
        return Json(new { message = ex.Message });
    }
    return Json(new { files = files });
}

This code is working with smaller files. My C# method gets called, the file is retrieved, and the progressall handler is called showing 100%.

The problem is when I attempt to upload a large file (where the progressall handler gets called more than once). In that case, the handler gets called with incrementing progress values up to 100%, as expected. But my C# method never gets called and the browser reports the following error.

POST http://localhost:1290/File/AddAttachment 404 (Not Found)

I'm confused by this error because the C# method is the same in both cases. Why is it found in one and not found in the other. I assume the issue is that my controller method is expecting a complete file and that I must instead write code to handle the upload in chunks. Is this right? Can anyone point me to documentation on how to write an upload handler using C#/MVC?

Answer 1

Dang it! It was an issue with the maximum file size being exceeded. I know this. I've dealt with it before. But I got confused by the 404 error! D'oh!

Answer 2

In fact, there is a trigger that depends on the incorrect opening of the high file which is not downloaded on its base.

The 404 error depends on the IIS security protocol

If you are going to examine the details of Request and Response, you can see it yourself

I do not recommend resolving it by the IIS administrator.

If you will set it at the application level

an example in web.config;

<System.webServer>
    <Security>
      <RequestFiltering>
        <requestLimits maxAllowedContentLength = "30000000" />
      </ requestFiltering>
    </ security>
  </system.webServer>