How to upload and read a CSV file in ASP.NET MVC3

What you can do is save the file on server, then after you read the content from them you can delete the file.

I think there is a no way you can read the from client side. You must upload it on ur server to read that.

using (StreamReader CsvReader = new StreamReader(input_file))
                {
                    string inputLine = "";

                    while ((inputLine = CsvReader.ReadLine()) != null)
                    {
                        values.Add(inputLine.Trim().Replace(",", "").Replace(" ", ""));
                    }
                    CsvReader.Close();
                    return values;
                }

You should be able to access the data without saving it - using the InputStream property

http://msdn.microsoft.com/en-us/library/system.web.httppostedfile.inputstream.aspx

and this (see Paulius Zaliaduonis answer)

    private async Task<string> ProcessAsync(string surveyId)
    {           if(!Request.Content.IsMimeMultipartContent())
        {
            return "|UnsupportedMediaType";
        }

        try
        {
            var provider = new MultipartMemoryStreamProvider();

            await Request.Content.LoadIntoBufferAsync().ConfigureAwait(false);
            await Request.Content.ReadAsMultipartAsync(provider).ConfigureAwait(false);

            HttpContent content = provider.Contents.FirstOrDefault();

            if(content != null)
            {
                Stream stream = await content.ReadAsStreamAsync().ConfigureAwait(false);

                using (StreamReader CsvReader = new StreamReader(stream))
                {
                    string inputLine = "";

                    while ((inputLine = CsvReader.ReadLine()) != null)
                    {
                        string[] vars = inputLine.Split(',');


                    }
                    CsvReader.Close();
                    //return values;
                }

            }
        }
        catch(Exception e)
        {
            return e.ToString();
        }

        return "Nothing To Process";
 }