asp.net mvc 3 - MVC. HttpPostedFileBase is always null

Question

I need some help. I'm trying to upload files using <input type="file">. Here is my View:

@using (Html.BeginForm("BookAdd", "Admin", FormMethod.Post, new { enctype = "multipart/form-data" }))
{
    <input type="file" name="files[0]" id="files[0]" />
    <input type="file" name="files[1]" id="files[1]" />
    <input type="submit" value="Upload Book" />
}

And here is an Action which should process uploaded file.

[HttpPost]
public ActionResult BookAdd(IEnumerable<HttpPostedFileBase> files)
{
    // some actions
    return View();
}

The problem is that "files" always contains two elements which are null. What can be done to fix it?

It's time for some news. It seems like I found the problem, but I still don't know how to fix it. It appears that despite the fact I'm using "multipart/form-data" here:

@using (Html.BeginForm("BookAdd", "Admin", FormMethod.Post, new { enctype="multipart/form-data" }))
{
    <input type="file" name="File" id="file1" />
    <input type="file" name="File" id="file2" />
    <input type="submit" value="Upload Book" />
}

Request.ContentType remains "application/x-www-forum-urlencoded" in controller..

Answer 1

The problem is that the NAME of the field need to match with the controller parameter. In your case is "files"... so your name attribute should be "files" also.