foreach on Request.Files

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];    ...}

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];

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.