File upload download

Clients and controllers are able to upload and download files. Here's how you can implement this on the client and on the server:

Controller side

On the controller side, you do not need to perform any special actions, work with files as in the original ASP.NET Core:

[HttpFacade, Path("api/[controller]")]
public interface IFileController
{
    [GetMethod("files/{id}")] Task<IActionResult> GetFileAsync([RouteParam] long id);
    [PostMethod("files")] Task PostFileAsync(byte[] fileBytes);
}

public class FileController : ControllerBase, IFileController
{
    public async Task<IActionResult> GetTextFileAsync(long id) => 
        PhysicalFile(physicalPath: "/TextFile.txt", contentType: "text/plain");

    public Task PostTextFileAsync(byte[] fileBytes) => 
        ...;
}

Client side

Since one method from the IFileController returns the IActionResult, it is necessary to override it using the IHttpResponse as the return value:

public interface IFileClient : IFileController
{
    [Override] new Task<IHttpResponse> GetFileAsync([RouteParam] long id);
}

After creating an interface for a client with an overridden method, you can create a client for downloading and uploading files:

IFileClient client = NClientGallery.Clients.GetRest()
    .For<IFileClient>(host: "http://localhost:8080")
    .Build();
    
var httpResponseWithFile = await client.GetFileAsync(id: 1);
var fileBytes = httpResponseWithFile.Content.Bytes;

var fileBytesForSave = ...;
await client.PostFileAsync(fileBytesForSave);

To work with streams, return a HttpResponseMessage instead of a IHttpResponse.