Failed to get a file. txt to download

Question

I have a method where after a query, I create a file. txt saving some parameters. My need is to get this . txt, where I will treat this file in a Javascript (Angularjs) to download.

But while trying to get that file, I get a return with the error:

exceptionMessage: "Process cannot access file 'E: nfs-and TEXT API users.txt' because it is being used by another process."

Back end where create and save the file . txt:

public HttpResponseMessage ObterNotas(UsuarioDTO user)
{
    var dataInicial = user.CompetenciaInicial;
    var dataFinal = user.CompetenciaFinal;

    var listaNotas = this.DbContext.ObterNotasRepo(dataInicial, dataFinal);

    string path = Path.GetDirectoryName(System.AppDomain.CurrentDomain.BaseDirectory.ToString());

    string new_dir = path + "/TEXT/"+ "users.txt";

    HttpResponseMessage response = null;

    if (!File.Exists(new_dir))
    {
        response = Request.CreateResponse(HttpStatusCode.Gone);
    }

    MemoryStream ms = new MemoryStream();

    List<string> lista = new List<string>();
    using (TextWriter writer = new StreamWriter(new_dir))
    {
        for (int i = 0; i < listaNotas.Count ; i++)
        {
            if (i == 0)
            {
                writer.Write(listaNotas[i].Usuario.CpfCnpj.ToString() + '|' + listaNotas[i].Usuario.RazaoSocial.ToString() + "\r\n");
            }
           writer.Write(listaNotas[i].NumeroRegistro.ToString() + "\r\n");
        }
        writer.Flush();

        response.Content = new ByteArrayContent(new_dir);
        response.Content.Headers.ContentDisposition = new ContentDispositionHeaderValue("attachment");
        response.Content.Headers.ContentType = new MediaTypeHeaderValue("application/pdf");
        response.Content.Headers.ContentDisposition.FileName = new_dir;

    }
    return response;
}

Javascript:

$scope.obterUsuario = function () 
{
    $scope.search.prestadorId = authService.authentication.user.codigo;
    userService.getUser($scope.search).then(function (result) {
      if (result.data.length > 0) {
        var data = result.data
        console.log(typeof (data));

        var headers = result.headers;
        headers = headers();

        var timeInMs = Date.now();

        var contentType = headers['content-type'];

        var linkElement = document.createElement('a');
        try {
          var blob = new Blob([data], { type: contentType });
          var url = window.URL.createObjectURL(blob);

          linkElement.setAttribute('href', url);
          linkElement.setAttribute("download", "teste" + '-' + timeInMs + ".txt");

          var clickEvent = new MouseEvent("click",
            {
              "view": window,
              "bubbles": true,
              "cancelable": false
            });
          linkElement.dispatchEvent(clickEvent);
          $modalInstance.dismiss('cancel');
        } catch (ex) {
          console.log(ex);
        }
      }
    });
}

Answer 1

Good your practice does not make much sense and the persistence of content in a text file before the answer, which will be overwritten at each execution and only serves to bring you competition problems.

Apart from testing to see if the file exists, you are not reading it anywhere else and at the end you are returning a txt file as if it were a pdf, which will only generate an invalid file.

It follows its code with a few minor adjustments, just to avoid some exceptions and to segregate minimante the writing and reading operations, which should not even be in the same method. But I really suggest you reevaluate your solution.

public HttpResponseMessage ObterNotas(UsuarioDTO user)
{
    var dataInicial = user.CompetenciaInicial;
    var dataFinal = user.CompetenciaFinal;

    var listaNotas = this.DbContext.ObterNotasRepo(dataInicial, dataFinal);

    string path =  Path.GetDirectoryName(System.AppDomain.CurrentDomain.BaseDirectory.ToString());

    string new_dir = path + "/TEXT/" + "users.txt";

    HttpResponseMessage response = new HttpResponseMessage();


    if (!File.Exists(new_dir))
    {
        response = Request.CreateResponse(HttpStatusCode.Gone);

    }


    List<string> lista = new List<string>();
    using (TextWriter writer = new StreamWriter(new_dir))
    {
        for (int i = 0; i < listaNotas.Count; i++)
        {
            if (i == 0)
            {
                writer.Write(listaNotas[i].Usuario.CpfCnpj.ToString() + '|' + listaNotas[i].Usuario.RazaoSocial.ToString() + "\r\n");
            }
            writer.Write(listaNotas[i].NumeroRegistro.ToString() + "\r\n");
        }
        writer.Flush();

    }

    var content = File.ReadAllBytes(new_dir);
    response.Content = new ByteArrayContent(content );
    response.Content.Headers.ContentDisposition = new ContentDispositionHeaderValue("attachment");
    response.Content.Headers.ContentType = new MediaTypeHeaderValue("application/text");
    response.Content.Headers.ContentDisposition.FileName = new_dir;

    return response;
}