JasCav JasCav - 3 months ago 11x
Javascript Question

Ajax form submission with files in ASP.NET MVC 6

I am using the jquery-ajax-unobtrusive library to add in the previously existing tag helpers for quickly creating a form that submits via an ajax request.

This gives me something like this:

<form id="person-create" enctype="multipart/form-data" asp-controller="Person" asp-action="Create" asp-route-id="1" data-ajax="true" data-ajax-method="POST" role="form">
<!-- There are other inputs for the other items. -->
<input id="photo-upload" asp-for="Photo" type="file">

The form submits great, except for the fact that a file input that I have within the form always comes through with a null value. As a test, I turned the form back to not use ajax and everything submits properly. I also tried to manually perform the submission by calling jQuery's
function directly, but, that also experienced the same issue as using jquery-ajax-unobtrusive.

My controller endpoint looks like this:

public async Task<IActionResult> Create(int id, PersonViewModel person)
// Do stuff...

And in PersonViewModel, I have a class that looks something like this:

public class PersonViewModel
public int PersonId { get; set; }
public string Name { get; set; }
public IFormFile Photo { get; set; }

Am I just missing something obvious, or is there something inherently different when submitting a file via an Ajax form submission?


Per Stephen's comment, jquery.unobtrusive-ajax cannot be used to submit files. Instead, the jQuery .ajax() method and FormData should be used to achieve this.

For more information, see Stephen's answer on another question.