File Input does not upload file to MVC Action

For a project i’ve been trying to upload a file from my view to my controller action.
However, for some reason the action is reached but for the file i receive a null.

Here is my code:

Action:

[HttpPost]
[Route("UploadSickNote")]
public ActionResult UploadSickNote(HttpPostedFileBase file)
{
    // Do something with file

    return RedirectToAction("SickNotes");
}

View:

<form Controller="Documents" Action="UploadSickNote" method="post">
    <div>
        <input id="sicknote-upload" name="UploadedSickNote" asp-for="UploadedSickNote" type="file" accept="image/*" capture>
        <input id="sicknote-button-submit" type="submit"/>
    </div>
</form>

I have also tried using a viewmodel but with the same results.

Action:

[HttpPost]
[Route("UploadSickNote")]
public ActionResult UploadSickNote(SickNotesViewModel vm)
{
    // Do something with file

    return RedirectToAction("SickNotes");
}

ViewModel:

public class SickNotesViewModel
{
    public List<SickNoteElement> SickNoteElements { get; set; }
    public HttpPostedFileBase UploadedSickNote { get; set; }
}

I am using asp.net mvc 5 (not asp.net core) and a bit of vue.js for view functionalities.
Any ideas or tips are greatly appreciated.

Answers:

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Method 1

Edit:

You have to make sure that your input name matches your controller so

<input id="sicknote-upload" name="file" asp-for="UploadedSickNote" type="file" accept="image/*" capture>

if with that doesnt work you could try also specifying the type of form you are sending

<form Controller="Documents" Action="UploadSickNote" method="post" enctype="multipart/form-data">

Method 2

Found the solution after some more searching.
I now receive the file in my viewmodel by changing my view to this:

   @using (Html.BeginForm("UploadSickNote", "Documents", FormMethod.Post, new { enctype = "multipart/form-data" }))
   {
            <div>
                <input id="sicknote-upload" name="UploadedSickNote" type="file" accept="image/*" capture>
                <input id="sicknote-button-submit" type="submit"/>
            </div>
   }

All methods was sourced from stackoverflow.com or stackexchange.com, is licensed under cc by-sa 2.5, cc by-sa 3.0 and cc by-sa 4.0