Copy files from one site collection to another - CSOM

Question

How to copy documents and files from one site collection to another site collection using CSOM code?

Answer 1

 public void CopyDocuments(string srcUrl, string destUrl, string destLibrary)
        {
            ClientContext srcContext = new ClientContext(srcUrl);

            ClientContext destContext = new ClientContext(destUrl);

            Web srcWeb = srcContext.Web;

            List srcList = srcWeb.Lists.GetByTitle(srcLibrary);

            Web destWeb = destContext.Web;

            destContext.Load(destWeb);

            destContext.ExecuteQuery();
            try
            {
                Microsoft.SharePoint.Client.File file = srcContext.Web.GetFileByServerRelativeUrl("/sites/Publishing/test.pdf");
                srcContext.Load(file);
                srcContext.ExecuteQuery();
                string location = destWeb.ServerRelativeUrl.TrimEnd('/') + "/" + destLibrary.Replace(" ", "") + "/" + file.Name;
                FileInformation fileInfo = Microsoft.SharePoint.Client.File.OpenBinaryDirect(srcContext, file.ServerRelativeUrl);
                Microsoft.SharePoint.Client.File.SaveBinaryDirect(destContext, location, fileInfo.Stream, true);
            }

            catch (Exception ex)
            {
                throw ex;
            }
        }

Method usage

CopyDocuments("URL1", "URL2", "Documents");