Upload multiple files using HttpFileCollectionBase issue with C# and MVC3

Question

I created a controller which save files.

The below code is a part of that Controller:

if ( Request.Files.Count != 0 ) {
      HttpFileCollectionBase files = Request.Files;

      foreach ( HttpPostedFileBase file in files ) {
            if ( file.ContentLength > 0 ) {
               if ( !file.ContentType.Equals( "image/vnd.dwg" ) ) {
                  return RedirectToAction( "List" );
               }
            }
         }
 }

in ASPX page is simple:

<input type="file" name="file" />
<input type="file" name="file" />
...// many inputs type file

The problem is foreach because it returns an error like (I know because I run in Debug mode and placed breakpoint at foreach statement):

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

What is my mistake ?

score 11 · Accepted Answer · answered Feb 29 '12 at 14:09

11

Try like this:

[HttpPost]
public ActionResult Upload(IEnumerable<HttpPostedFileBase> files)
{
    if (files != null && files.Count() > 0)
    {
        foreach (var uploadedFile in files)
        {
            if (uploadedFile.ContentType != "image/vnd.dwg") 
            {
                return RedirectToAction("List");
            }

            var appData = Server.MapPath("~/app_data");
            var filename = Path.Combine(appData, Path.GetFileName(uploadedFile.FileName));
            uploadedFile.SaveAs(filename);                    
        }
    }

    return RedirectToAction("Success");
}

and modify the markup so that the file inputs are named files:

<input type="file" name="files" />
<input type="file" name="files" />
...// many inputs type file

answered Feb 29 '12 at 14:09

Darin Dimitrov

1,023,142
271
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I tried the above code (it seems with my code) but I changed my mind regarding to `foreach`. I'm using now the `for` statement. And it works good. – Snake Eyes Feb 29 '12 at 14:11
and the last mention: I have no parameters in my controller function – Snake Eyes Feb 29 '12 at 14:13
I tried this solution but I don't retrieve any value! – HelloWorld1 Dec 23 '15 at 11:50

Henry · Answer 2 · 2017-03-14T03:32:29.160

3

for (int i = 0; i < Request.Files.Count; i++)
{
    var file = Request.Files[i];
    // this file's Type is HttpPostedFileBase which is in memory
}

HttpRequestBase.Files requires an index, so use for instead of foreach.

edited Mar 14 '17 at 03:32

answered Jul 12 '16 at 03:13

Henry

31
4

score 2 · Answer 3 · answered Feb 29 '12 at 14:10

2

Have a look at this post by Phil Haack which demonstrates how to process multiple file uploads using MVC. The object you are trying to use is for ASP.NET Webforms.

answered Feb 29 '12 at 14:10

Lazarus

41,906
4
43
54

Upload multiple files using HttpFileCollectionBase issue with C# and MVC3

3 Answers3

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