How to POST an attachment via Visma.net API in C# ?

[#1]

Please see attachment specific endpoints at https://integration.visma.net/API-index/

Webclient Class

public void postAttachment(string[] files, string <objectID>, string token, string companyId)
        {
            using (WebClient client = new WebClient())
            {
               
                    client.Headers.Add("ipp-company-id", "<companyId>");
                    client.Headers.Add("ipp-application-type", "Visma.net Financials");
                    client.Headers.Add("Authorization", "bearer<token>");
            
                    for (int i = 0; i < files.Length; i++) // Multiple
                    {
byte[] responseArray =        client.UploadFile(@"https://integration.visma.net/API/controller/api/v1/<Endpoint>/"+<objectID>+"/Attachment", "POST", files[i]);   
                    
                    }
        }
}

HttpClient Class

 public void postAttachmentHttpClient()
        {
                using (var client = new HttpClient())
                {
 
                    client.DefaultRequestHeaders.Add("ipp-application-type", "Visma.net Financials");
                    client.DefaultRequestHeaders.Add("ipp-company-id", "<companyID>");
                    client.DefaultRequestHeaders.Add("Authorization", "Bearer <token>");

                    HttpResponseMessage response;
                    var content = new MultipartFormDataContent();

                    var path = Path.Combine(@"<path>");
                    string fileName = Path.GetFileName(path);

                    FileStream fs = File.OpenRead(path);
                    var sc = new StreamContent(fs);

                    sc.Headers.Add("Content-Type", "application/octet-stream");
                    sc.Headers.Add("Content-Disposition","form-data; name=\"file\"; filename=\"" +       Path.GetFileName(path) + "\"");
                    
                    content.Add(sc, "file", fileName);
                    response = client.PostAsync(@"https://integration.visma.net/API/controller/api/v1/<endpoint>/<objectID>/Attachment", content).Result;

                }
            }

Disclaimer
The sample code on Visma Community > Visma.Net API is provided “AS IS” and any express or implied warranties, including the implied warranties of merchantability and fitness for a particular purpose, are disclaimed. In no event shall Visma or contributors be liable for any direct, indirect, incidental, special, exemplary or consequential damages.