How in asp.net core webapi project you can pass multiple parameters to a controller where one of them is file or a byte[]

Question

Can any one point me in the right direction, which is the best way to pass in asp.net core multiple parameters to a webapi controller where one of them is an image?

I know that in MVC you can do something like this

public ActionResult Index(IEnumerable<HttpPostedFileBase> files, FormCollection form)
{
}

instead of an IEnumerable and the FormCollection I would like to do something like this

public ActionResult Index(byte[] file, string name, DateTime createdDate )

1. Do I need to write a model binder?
2. How using the postman I can make a post to that later method?

Answer 1

You can't post a byte[] . The ASP.NET Core equivalent of HttpPostedFileBase is IFormFile .

You shouldn't use FormCollection . Instead, create a view model that you can bind to, which houses all the properties you're posting. You can also include your file upload property within this view model as well. For example:

public class MyViewModel
{
    public IFormFile File { get; set; }
    public string Name { get; set; }
    public DateTime CreatedDate { get; set; }
} 

Then:

public IActionResult Index(MyViewModel model)

ASP.NET Core doesn't support posting via multiple different ways (HTML form, JSON, etc.) on the same action. You don't need to do anything special for a regular old HTML form post, but for posting something like JSON, you'd have to decorate your action param with [FromBody] :

public IActionResult Index([FromBody]MyViewModel model)

Posting with Postman, you can post as x-www-form-urlencoded or multipart/form-data (the same as a normal form post), but if you need to post JSON from there and accept a post from an HTML form, you'll need two separate actions: one with the [FromBody] attribute and one without. You can largely factor out the contents of the action into a common method both can use to prevent code duplication:

[HttpPost("api/index")]
public IActionResult IndexApi([FromBody]MyViewModel model)
    => IndexCore(model);


[HttpPost("index")]
public IActionResult Index(MyViewModel model)
    => IndexCore(model);

protected IActionResult IndexCore(MyViewModel model)
{
    // action code here
}

Answer 2

for file you need to use

List<IFormFile> files

other parameters can bu used in the same way.

In ASP.NET Core, you can also use

[FromRoute]
[FromQuery]
[FromBody]
[FromHeader]
[FromForm]