Conversion of Byte to PDF using ConvertAPI

Question

Our requirement is to convert file stored in database, array of byte to PDF using ConvertAPI. We have tried multiple options but getting different errors as mention below. Can someone please help us with function to convert Byte file format to PDF.

Error 1 - The remote server returned an error: (400) Bad Request.

  using (var client = new WebClient())
            {
                client.Headers.Add("accept", "application/octet-stream");
                client.Headers.Add("Content-Type", "application/x-www-form-urlencoded");
                var resultFile = client.UploadData("https://v2.convertapi.com/doc/to/pdf?Secret=**********", byteTemplate);
            }
 

Error 2 - The remote server returned an error: (400) Bad Request

      var requestContent = new MultipartFormDataContent();
        ByteArrayContent data = new ByteArrayContent(byteTemplate, 0, byteTemplate.Count());
        requestContent.Add(data, "File", "Files");
        requestContent.Add(new StringContent("**********"), "Secret");
        var authParam = parameters.ContainsKey("secret") ? $"Secret={parameters["secret"]}" : $"Token={parameters["token"]}";
        return new HttpClient().PostAsync($"https://v2.convertapi.com/{srcFormat}/to/{dstFormat}?{authParam}", requestContent).Result;

Error 3 - Code":5001,"Message":"Conversion failed."

or Cannot access a disposed object. Object name: 'System.Net.Http.MultipartFormDataContent'

public static HttpResponseMessage Convert(string srcFormat, string dstFormat, Dictionary<string, string> parameters, byte[] bytetemp, MemoryStream streamTemplate)
    {
        var requestContent = new MultipartFormDataContent();
        streamTemplate.Position = 0;
        requestContent.Add(new StreamContent(streamTemplate), "File", "ABC");
        foreach (var parameter in parameters)
        {
            if (File.Exists(parameter.Value))
            {
            }
            else
            {
                requestContent.Add(new StringContent(parameter.Value), parameter.Key);
            }
        }
        var authParam = parameters.ContainsKey("secret") ? $"Secret={parameters["secret"]}" : $"Token={parameters["token"]}";
        HttpContent rescont = new HttpClient().PostAsync($"https://v2.convertapi.com/{srcFormat}/to/{dstFormat}?{authParam}", requestContent).Result.Content;
        String a = rescont.ReadAsStringAsync().Result;
    }

Error 4 - The remote server returned an error: (400) Bad Request.

Old Code with New URL, Working with old URL

public static byte[] CovertWordtoPdf(byte[] response)
    {
        byte[] bufferDocxReport;
        bufferDocxReport = response;

        string reportName = "reportname.doc";
        #region Convert DOCX report to PDF format
       WebRequest convertToPdfRequest = WebRequest.Create("https://v2.convertapi.com/docx/to/pdf?Secret=************");
        convertToPdfRequest.Method = "POST";
        var boundary = "---------------------------" + DateTime.Now.Ticks.ToString("x", NumberFormatInfo.InvariantInfo);
        convertToPdfRequest.ContentType = "multipart/form-data; boundary=" + boundary;
        boundary = "--" + boundary;
        using (var requestStream = convertToPdfRequest.GetRequestStream())
        {
            // Write the file
            var buffer = Encoding.ASCII.GetBytes(boundary + Environment.NewLine);
            requestStream.Write(buffer, 0, buffer.Length);
            buffer = Encoding.UTF8.GetBytes(string.Format("Content-Disposition: form-data; name=\"{0}\"; filename=\"{1}\"{2}", "name", reportName, Environment.NewLine));
            requestStream.Write(buffer, 0, buffer.Length);
            buffer = Encoding.ASCII.GetBytes(string.Format("Content-Type: {0}{1}{1}", "application/octet-stream", Environment.NewLine));
            requestStream.Write(buffer, 0, buffer.Length);
            requestStream.Write(bufferDocxReport, 0, bufferDocxReport.Length);
            buffer = Encoding.ASCII.GetBytes(Environment.NewLine);
            requestStream.Write(buffer, 0, buffer.Length);
            var boundaryBuffer = Encoding.ASCII.GetBytes(boundary + "--");
            requestStream.Write(boundaryBuffer, 0, boundaryBuffer.Length);
        }

        using (var convertToPdfResponse = convertToPdfRequest.GetResponse())
        using (Stream convertToPdfResponseStream = convertToPdfResponse.GetResponseStream())
        {
            bufferDocxReport = ReadToEnd(convertToPdfResponseStream);
        }

        return bufferDocxReport;
        #endregion
    }   

Error 5 - Code:5001,Message:"Conversion failed.

var requestContent = new MultipartFormDataContent();
        streamTemplate.Position = 0;
        StreamContent data = new StreamContent(streamTemplate);
        requestContent.Add(data, "File", "Files");
        requestContent.Add(new StringContent("************"), "Secret");
        var authParam = parameters.ContainsKey("secret") ? $"Secret={parameters["secret"]}" : $"Token={parameters["token"]}";
        return new HttpClient().PostAsync($"https://v2.convertapi.com/{srcFormat}/to/{dstFormat}?{authParam}", requestContent).Result;

Answer 1

The working solution would be

const string fileToConvert = @"C:\Projects\_temp\test1.docx";
var bytesToConvert = File.ReadAllBytes(fileToConvert);

var url = new Uri("https://v2.convertapi.com/docx/to/pdf?secret=<YourSecret>");                       
var content = new ByteArrayContent(bytesToConvert);
content.Headers.Add("content-type", "application/octet-stream");
content.Headers.Add("content-disposition", "attachment; filename=\"test1.docx\"");          
var fileBytes = new HttpClient().PostAsync(url, content).Result.Content.ReadAsByteArrayAsync().Result;     

I would like to point several important things:

• We should set content-type for request to application/octet-stream because we send plain binary data in request body.
• Also content-disposition should be provided to let Rest API endpoint to know what data is sent, in this case it is file.