Upload Document to a doc set using Managed Client Object Model

Below function uploads any file to a docset using Client object modeling.


 public void UploadDocument(string siteurl, string listname, string docsetname, string filename)
        {
           
            using (ClientContext clientContext = new ClientContext(siteurl))
            {
                //Get Document List
                List documentsList = clientContext.Web.Lists.GetByTitle(HttpUtility.UrlDecode(listname));


                var fileCreationInformation = new FileCreationInformation();
                //Assign to content byte[] i.e. documentStream


                fileCreationInformation.Content = System.IO.File.ReadAllBytes( filename )); ;
                //Allow owerwrite of document


                fileCreationInformation.Overwrite = true;
                //Upload URL


                fileCreationInformation.Url = siteurl + "/" + listname + "/" + docsetname + "/" +  filename";
                Microsoft.SharePoint.Client.File uploadFile = documentsList.RootFolder.Files.Add(fileCreationInformation);


                uploadFile.ListItemAllFields.Update();
                clientContext.ExecuteQuery();


            }
        }

Call the above function as below

UploadDocument("https://testsite", "test Library", "My Doc Set", "C:\test.ppt");

if you look at the code above we are reading the bytes from the file(which is in the client machine) and uploading it using the Microsoft.SharePoint.Client.File class.