foreach on Request.Files

Question

I'm attempting upload multiple files in ASP.NET MVC and I have this simple foreach loop in my controller

foreach (HttpPostedFileBase f in Request.Files)
{
    if (f.ContentLength > 0)
        FileUpload(f);
}

The previous code generates this error:

Unable to cast object of type 'System.String' to type 'System.Web.HttpPostedFile'.

What I don't understand is why Request.Files[1] returns an HttpPostedFileBase but when it's iterated over, it returns strings (presumably the file names).

Note: I know this can be solved with a for loop. Also, I tried using HttpPostedFile, with the same error.

tvanfosson · Accepted Answer · 2013-06-04T19:54:43.927

118

The enumerator on the HttpFileCollection returns the keys (names) of the files, not the HttpPostedFileBase objects. Once you get the key, use the Item ([]) property with the key (filename) to get the HttpPostedFileBase object.

foreach (string fileName in Request.Files)
{
    HttpPostedFileBase file = Request.Files[fileName];

    ...
}

edited Jun 04 '13 at 19:54

answered Nov 19 '09 at 02:30

tvanfosson

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Is there a way to have it return an HttpPostedFile instead? – Omar Nov 19 '09 at 02:35
Not that I know of. It derives from NameObjectCollectionBase and the enumerator for that class iterates over the keys. – tvanfosson Nov 19 '09 at 11:33
The compiler throws an error for me and wants me to use `HttpPostedFileBase` instead of `HttpPostedFile`. – Cody Jun 04 '13 at 19:36
@tvanfosson in my case fileName always becomes "Image", but when I say Request.Files[0].FileName it gives the correct name any idea? I'm using MVC5. – Geethanga Mar 22 '14 at 04:36
1

@Geethanga - the "name" that is the key is the name on the HTML file input tag, it's not the name of the file that is uploaded. – tvanfosson Mar 22 '14 at 14:55
I'd caution anyone using this answer that this was a problem for us on iOS because the "take photo" feature names every file "image.jpg." I'd recommend @harvey 's answer below. – Brian Davis Jul 13 '20 at 16:30
@tvanfosson in my case its saving first file xtimes the x number of files uploaded – Heemanshu Bhalla Sep 02 '20 at 01:38

score 40 · Answer 2 · answered Dec 08 '14 at 04:23

40

With my tab HTML is:

<input class="valid" id="file" name="file" multiple="" type="file">

Request.Files will have duplicate name in array. So you should solve like this:

for (int i = 0; i < Request.Files.Count; i++ ){
    HttpPostedFileBase fileUpload = Request.Files[i];

answered Dec 08 '14 at 04:23

nguyenhoai890

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This one worked better for me than the answer because, as their html points out, it allows for multiple files in the same file input. – Caffeinius Sep 29 '15 at 17:53
5

This is the correct answer as you should be able to get the filename with `file.FileName`. If you do it with `foreach` and have duplicate names the first file will be saved multiple times – Arijoon May 03 '16 at 11:02

Akira Yamamoto · Answer 3 · 2017-06-13T23:53:22.793

15

We can use LINQ to do this and still use foreach as asked:

var files = Enumerable.Range(0, Request.Files.Count)
    .Select(i => Request.Files[i]);

foreach (var file in files)
{
    // file.FileName
}

As @tvanfosson said, the enumerator returns the file names as strings, not the HttpPostedFileBase. This method HttpPostedFileBase this[string name] returns the object we want. If HttpFileCollectionBase implemented IEnumerable<HttpPostedFileBase> then we could do the foreach normally. However, it implements a non-generic IEnumerable.

edited Jun 13 '17 at 23:53

answered Sep 30 '15 at 23:01

Akira Yamamoto

4,685
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Super :-) :-). Working Fine – Thulasiram May 06 '21 at 11:35

score 6 · Answer 4 · answered Nov 19 '09 at 02:30

6

You might try iterating the strings and casting them to HttpPostedFile instead, like this:

foreach (string file in Request.Files)
    {
        HttpPostedFile hFile = Request.Files[file] as HttpPostedFile;
        if (hFile.ContentLength > 0)
            FileUpload(hFile);
    }

answered Nov 19 '09 at 02:30

Joe Barone

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cannot implicitly convert HttpPostedFileBase to HttpPostedFile – Ifeanyi Chukwu Dec 16 '13 at 10:35

score 6 · Answer 5 · answered Oct 09 '14 at 12:46

Unfortunately tvanfosson's answer did not work for me. Although the files would upload just fine, and no error would be thrown, a problem would occur where only one of the files would be used, so the same file would be saved twice rather than using them both.

It seemed to be a problem with the foreach statement looping through the names of each file in the Request.Files, for some reason it wasn't working as a key for me, and only the first file would be selected every time.

HttpFileCollectionBase files = Request.Files;

for(var i = 0; i < files.Count; i++)
{
    HttpPostedFileBase file = files[i];

    ...
}

This was a problem for us on iOS because the "take photo" feature names every file "image.jpg" - but this change resolved it. Thank you. — Brian Davis, Jul 13 '20 at 16:28

score 6 · Answer 6 · edited Aug 30 '16 at 06:20

The following code worked for me.

  HttpResponseMessage result = null;
  var httpRequest = System.Web.HttpContext.Current.Request;
  HttpFileCollection uploadFiles = httpRequest.Files;
  var docfiles = new List<string>();

  if (httpRequest.Files.Count > 0){
      int i;
      for (i = 0; i < uploadFiles.Count; i++) {
          HttpPostedFile postedFile = uploadFiles[i];
          var filePath = @"C:/inetpub/wwwroot/test1/reports/" + postedFile.FileName;
          postedFile.SaveAs(filePath);
          docfiles.Add(filePath);
      }
      result = Request.CreateResponse(HttpStatusCode.Created, docfiles);
  } else {
      result = Request.CreateResponse(HttpStatusCode.BadRequest);
  }

  return result;
}

score 0 · Answer 7 · answered Jan 24 '19 at 08:43

0

You can get the HttpPostedFile out of the HttpFileCollection using foreach like this:

foreach (var obj in fileCollection)
{
    HttpPostedFile file = fileCollection.Get(obj.ToString());
}

answered Jan 24 '19 at 08:43

Jnr

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foreach on Request.Files

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