WebAPI File Uploading – Without writing files to disk

Solved:

Use the existing simple MultipartMemoryStreamProvider. No custom classes or providers required. This differers from the duplicate question which solved the solution by writing a custom provider.

Then use it in a WebAPI handler as so:

public async Task<IHttpActionResult> UploadFile()
{
    if (!Request.Content.IsMimeMultipartContent())
    {
        return StatusCode(HttpStatusCode.UnsupportedMediaType);
    }        
  
    var filesReadToProvider = await Request.Content.ReadAsMultipartAsync();
    
    foreach (var stream in filesReadToProvider.Contents)
    {
        var fileBytes = await stream.ReadAsByteArrayAsync();
    }
    return StatusCode(HttpStatusCode.OK);
}