static void Import(string file, string folder) { ErpFile erp = new ErpFile(); erp.Read(File.Open(file, FileMode.Open, FileAccess.Read, FileShare.Read)); erp.ProgressStatus = new Progress <string>(status => { _stringBuilder.Append(status); }); Task.Run(() => erp.Import(Directory.GetFiles(folder, "*", SearchOption.AllDirectories))).Wait(); Task.Run(() => erp.Write(File.Open(file, FileMode.Create, FileAccess.Write, FileShare.Read))).Wait(); }