Uploading Files with ASP.Net MVC - get name but no file stream, what am I doing wrong?

Question

I have this form in my view:

<!-- This has a bug right here--v  Don't copy this without removing the extra i-->
<form method="post" enctype="mulitipart/form-data" action="/Task/SaveFile">
<input type="file" id="FileBlob" name="FileBlob"/>
<input type="submit"  value="Save"/>
<input type="button" value="Cancel" onclick="window.location.href='/'" />
</form>

And this code in my controller:

public ActionResult SaveFile( FormCollection forms )
{
   bool errors = false;
   //this field is never empty, it contains the selected filename
   if ( string.IsNullOrEmpty( forms["FileBlob"] ) )
   {
       errors = true;
       ModelState.AddModelError( "FileBlob", "Please upload a file" );
   }
   else
   {
      string sFileName = forms["FileBlob"];
      var file = Request.Files["FileBlob"];
      //'file' is always null, and Request.Files.Count is always 0 ???
      if ( file != null )
      {
         byte[] buf = new byte[file.ContentLength];
         file.InputStream.Read( buf, 0, file.ContentLength );
         //do stuff with the bytes
      }
      else
      {
         errors = true;
         ModelState.AddModelError( "FileBlob", "Please upload a file" );
      }
   }
   if ( errors )
   {
      return ShowTheFormAgainResult(); 
   }
   else
   {
      return View();
   }
}

Based on every code sample I've been able to find, this seems like the way to do it. I've tried with small and large files, with no difference in the result. The form field always contains the filename which matches what I've chosen, and the Request.Files collection is always empty.

I don't think it's relevant, but I'm using the VS Development Web Server. AFAIK it supports file uploads the same as IIS.

It's getting late and there's a chance I'm missing something obvious. I'd be grateful for any advice.

Answer 1

var file = Request.Files[sFileName];

should be...

var file = Request.Files["FileBlob"];

that said, Request.Files.Count should be 1 ... hmmm

Answer 2

I don't know what the policy is on posting profanity, but here's the problem:

enctype="mulitipart/form-data"

The extra i in there stopped the file from uploading. Had to run Fiddler to see that it was never sending the file in the first place.

It should read:

enctype="multipart/form-data"

Answer 3

Good that you found your error.

As a side note you'll want a try/catch around the file handling code so you'll know when file permissions etc. are not setup correctly.

Answer 4

For people who may stumble on to this post in the future, here a great post by Scott Hanselman on the subject: A Back To Basics Case Study: Implementing HTTP File Upload with ASP.NET MVC including Tests and Mocks

Answer 5

Obscure strings...