How to make other methods call after return OK response to client in ASP.Net Core

Question

I am using the asp.net core WebAPI Project in which a client is uploading some files to a server. The whole uploading is done using chunks.

The problem is when I am uploading a huge file then I am getting a response after a very long time. So what I want to do is when all the chunks are uploaded on a server then send an OK response to the client and do the chunks merging related stuff after the OK response.

Here is my code:

public async Task<ActionResult> Upload(int currentChunkNo, int totalChunks, string fileName)
{
            try
            {
                string newpath = Path.Combine(fileDirectory + "/Chunks", fileName + currentChunkNo);
                using (FileStream fs = System.IO.File.Create(newpath))
                {
                    byte[] bytes = new byte[chunkSize];
                    int bytesRead = 0;
                    while ((bytesRead = await Request.Body.ReadAsync(bytes, 0, bytes.Length)) > 0)
                    {
                        fs.Write(bytes, 0, bytesRead);
                    }
                }
                return Ok(repo.MergeFile(fileName));
            }
            catch (Exception ex)
            {
                return BadRequest(ex);
            }
}

Answer 1

You can use middleware for process after action run.

First create your middleware

public class UploadMiddleware
{
    private readonly RequestDelegate _next;

    public UploadMiddleware(RequestDelegate next)
    {
        _next = next;
    }

    // you can inject services here

    public async Task InvokeAsync(HttpContext httpContext)
    {
        // before request

        await _next(httpContext);

        // YourController/Upload is your path on route
        // after any action ended
        if (httpContext.Response != null &&
            httpContext.Response.StatusCode == StatusCodes.Status200OK &&
            httpContext.Request.Path == "YourController/Upload") 
        { 
            // another jobs
        }

    }
}

Use Middleware

app.UseMiddleware<UploadMiddleware>();