cms_thermo_active/Thermo.Active/Provider/CustomMultipartFormDataStreamProvider.cs

using System;
using System.IO;
using System.Net;
using System.Net.Http;
using System.Net.Http.Headers;
using System.Threading;
using System.Threading.Tasks;
using System.Web;
using System.Web.Http;

namespace Thermo.Active.Provider
{
    public class FileResult : IHttpActionResult
    {
        private readonly string FilePath;
        private readonly string ContentType;
        private readonly string FileName;

        public FileResult(string filePath, string contentType = null, string fileName = null)
        {
            FilePath = filePath;
            ContentType = contentType;
            FileName = fileName;
        }

        public Task<HttpResponseMessage> ExecuteAsync(CancellationToken cancellationToken)
        {
            return Task.Run(() =>
            {
                // Create response
                var response = new HttpResponseMessage(HttpStatusCode.OK)
                {
                    Content = new StreamContent(File.OpenRead(FilePath)) // Set file
                };
                // Set header content type
                var contentType = ContentType ?? MimeMapping.GetMimeMapping(Path.GetExtension(FilePath));
                response.Content.Headers.ContentType = new MediaTypeHeaderValue(contentType);

                response.Content.Headers.ContentDisposition = new ContentDispositionHeaderValue("inline")
                {
                    FileName = FileName
                };

                return response;
            }, cancellationToken);
        }
    }

    // Override MultipartFormDataStreamProvider to override the GetLocalFileName
    public class CustomMultipartFormDataStreamProvider : MultipartFormDataStreamProvider
    {
        public CustomMultipartFormDataStreamProvider(string path) : base(path)
        {
        }

        public override string GetLocalFileName(HttpContentHeaders headers)
        {
            var fileName = headers.ContentDisposition.FileName.Replace("\"", string.Empty);

            return Path.GetFileNameWithoutExtension(fileName) + Guid.NewGuid() + Path.GetExtension(fileName);
        }
    }
}