Programmatically Add/Upload a file to Document Library in SharePoint 2010

Simple steps to upload a file programmatically to SPDocumentLibrary in SharePoint 2010

SPSecurity.RunWithElevatedPrivileges(delegate()

                {

                    using (SPSite site = new SPSite(guidSiteID))

                    {

                        using (SPWeb web = site.OpenWeb())

                        {

                            SPDocumentLibrary documentLib = web.Lists.TryGetList(strAFE_Attachments) as SPDocumentLibrary;

                            Stream fStream = fupAttachment.PostedFile.InputStream;

                            byte[] _byteArray = new byte[fStream.Length];

                            fStream.Read(_byteArray, 0, (int)fStream.Length);

                            fStream.Close();

                            web.AllowUnsafeUpdates = true;

                            string _fileUrl = documentLib.RootFolder.Url + "/" + Path.GetFileNameWithoutExtension(fupAttachment.PostedFile.FileName) + DateTime.Now.ToString("MMddyyyyHHmmss") + Path.GetExtension(fupAttachment.PostedFile.FileName);

                            bool IsOverwriteFile = false;

                            SPFile file = documentLib.RootFolder.Files.Add(_fileUrl, _byteArray, IsOverwriteFile);

                            SPListItem item = file.Item;

                            item["Title"] = _strAFE_No;

                            item.Update();

                            file.Update();

                            web.AllowUnsafeUpdates = false;

                        }

                    }

                });

Adding Folder and SubFolder to document library in SharePoint 2010

SPSecurity.RunWithElevatedPrivileges(delegate()

                {

                    using (SPSite site = new SPSite(guidSiteID))

                    {

                        using (SPWeb web = site.OpenWeb())

                        {

                            SPDocumentLibrary documentLib = web.Lists.TryGetList(strAFE_Attachments) as SPDocumentLibrary;

                           

                            #region  Folder Creation

                            web.AllowUnsafeUpdates = true;

                            SPListItem newFolder = documentLib.Items.Add("", SPFileSystemObjectType.Folder, "TestRootFolder");

                            newFolder.Update();

                            //Creating Subfolder inside folder

                            string subFolderUrl = web.Url + "/" + newFolder.Url;

                            SPListItem subFolder = documentLib.Items.Add(subFolderUrl, SPFileSystemObjectType.Folder, "TestSubFolder");

                            subFolder.Update();

                            web.AllowUnsafeUpdates = false;

                            #endregion

                        }

                    }

                });