I am working on converting a ASP.NET MVC application over to ASP.NET Core 9.0 MVC. It is going pretty well so far, but I am at the point where I need to allow my users to upload files and read files from a directory. In ASP.NET, I would create a virtual directory in IIS (/files/) and all files that are dynamically created from the system or uploaded by users would be somewhere inside there. This virtual directory may point to one physical path on live, a different spot for staging, and another spot on any developer machines.

From what I am reading so far, it seems like virtual directories may not be supported in ASP.NET Core, but I don't really understand how to mimic that functionality. I need the path to be different based on which version of the application it is (live, staging, dev). I don't want it to be a folder that is a part of the project as I don't want any publish issues. What is the best way to proceed?

I am working on converting a ASP.NET MVC application over to ASP.NET Core 9.0 MVC. It is going pretty well so far, but I am at the point where I need to allow my users to upload files and read files from a directory. In ASP.NET, I would create a virtual directory in IIS (/files/) and all files that are dynamically created from the system or uploaded by users would be somewhere inside there. This virtual directory may point to one physical path on live, a different spot for staging, and another spot on any developer machines.

From what I am reading so far, it seems like virtual directories may not be supported in ASP.NET Core, but I don't really understand how to mimic that functionality. I need the path to be different based on which version of the application it is (live, staging, dev). I don't want it to be a folder that is a part of the project as I don't want any publish issues. What is the best way to proceed?

• asp-core

1 Answer 1

You could host static files of a folder directly by:

var externalFilePath = builder.Configuration.GetValue<string>("ExternalFilePath");
var fileProvider = new PhysicalFileProvider(externalFilePath);
var requestPath = "/files";
app.UseStaticFiles(new StaticFileOptions
{
    FileProvider = fileProvider,
    RequestPath = requestPath,
    //ServeUnknownFileTypes = true // Only if needed
});
// for directory browsing
app.UseDirectoryBrowser(new DirectoryBrowserOptions
{
    FileProvider = fileProvider,
    RequestPath = requestPath
});

Then you add different path to json file of different enviroment. appsettings.Development.json appsettings.staging.json appsettings.prod.json

"ExternalFilePath": "C:\\ExternalFiles"

And you will need to create api endpoint to upload file to this folder

[ApiController]
[Route("api/files")]
public class FileUploadController : ControllerBase
{
    private readonly string _externalPath;

    public FileUploadController(IConfiguration configuration)
    {
        _externalPath = configuration.GetValue<string>("ExternalFilePath") 
                        ?? throw new Exception("External file path not configured");
    }

    [HttpPost("upload")]
    public async Task<IActionResult> UploadFile(IFormFile file)
    {
        if (file == null || file.Length == 0)
            return BadRequest("No file uploaded.");

        string filePath = Path.Combine(_externalPath, file.FileName);

        using (var stream = new FileStream(filePath, FileMode.Create))
        {
            await file.CopyToAsync(stream);
        }

        return Ok(new { FilePath = filePath });
    }
}