File not being released after upload

Question

Using Asp.Net MVC, I'm uploading a zip file and extracting it using the following method, and there seems to be a process still attached to it, as I cannot delete it in Windows Explorer after processing.

Here's the controller post:

[HttpPost]
public ActionResult ImportZip(HttpPostedFileBase zip)
{
    try
    {
        if (zip == null)
            throw new Exception("Please select a file to import");

        var result = new ContentManagementImporter(EducorDbRepo).ImportZipFile(zip);

        ViewData[ViewDataKeys.SuccessMessage] = result;
        return View("Import");
    }
    catch (Exception ex)
    {
        SetViewError(ex);
        return View("Import");
    }
}

And here's the method that process the uploaded file:

private static Dictionary<string, string> UnzipFiles(HttpPostedFileBase zipFile)
{
    var files = new Dictionary<string, string>();

    using (var archive = new ZipArchive(zipFile.InputStream))
    {
        foreach (var file in archive.Entries)
        {
            if (file == null)
                continue;

            using (var stream = file.Open())
            using (var reader = new StreamReader(stream))
            {
                var markup = reader.ReadToEnd();
                files.Add(file.Name, markup);
            }
        }
    }

    zipFile.InputStream.Close();

    return files;
}

Can you see where in the code I'm failing to close something that needs to be closed, or is there another reason?

Answer 1

The server behaviour can't lock files on the client. As such, I am 90% sure any locking you are seeing is caused by the browser itself (and thus outside your control).

You may want to consider trying an alternate browser and seeing what happens.