Convert File in JSON Reply

Question

I have to use JSON to query a remote site for files. The query specifies a customer number and the reply sends back files for that customer. I get the JSON reply and it includes what I think is the file inside the reply. I assume that I have to remove the JSON part of the reply. My question is how do I convert the response to a file, .PDF for example, that I can save and open later? This is all done without using a browser and most of the results from my searches seem to use one. My current query routine is:

void JSONPost(string _url, string _data, TextBox resultBox)
        {
            var url = _url;
            var httpRequest = (HttpWebRequest)WebRequest.Create(url);
            httpRequest.Method = "POST";
            httpRequest.Accept = "application/json";
            httpRequest.ContentType = "application/json";
            httpRequest.Headers["Authorization"] = "Bearer XXXXXXXXXXXXXXXXXXXXX";
            var data = _data;

            using (var streamWriter = new StreamWriter(httpRequest.GetRequestStream()))
            {
                streamWriter.Write(data);
            }

            var httpResponse = (HttpWebResponse)httpRequest.GetResponse();
            using (var streamReader = new StreamReader(httpResponse.GetResponseStream()))
            {
                queryResult = streamReader.ReadToEnd();
                resultBox.Text = queryResult.Substring(0, 50);
            }
        }

Answer 1

I found that I had to perform several steps to solve: First I moved the actual file data to a new string. Then I had to remove the backslashes from the new string. I then converted the Base64 string into an array. And finally, I wrote that string to the destination file.