POST Multiple Images

demo.cs

[HttpPost]
public async Task<JsonResult> MyAction(IEnumerable<HttpPostedFileBase> files)
{
    // Do stuff
 
    ...

    return new JsonResult() { Data = 'Ok' };
}

demo.html

<form class="js-my-form" action="/my-action" method="post" enctype = "multipart/form-data">
    <input type="file" class="js-file-upload" name="files" accept=".pdf,.doc,.docx,.jpg,.jpeg,.gif,.png" multiple>
    <input type="submit" value="Submit" />
</form>

demo.js

$('.js-my-form').submit(function (e) {
    e.preventDefault();
    // Wrap form in a FormData object see:- https://developer.mozilla.org/en-US/docs/Web/API/FormData
    var formData = new FormData($(this)[0]);
    
    $.ajax({
        url: '/my-action',
        data: formData,
        //ContentType: false is important.
        contentType: false,
        //processType: false is important.
        processData: false,
        type: 'POST',
        success: function () {
            console.log('Done!');
            }})                 
});