public static void Close() { if (StockDB.dtSymbolListChanged) { StockDB.SaveDB(StockDB.dtSymbolList); } if (StockDB.dtFolderAllChanged) { StockDB.SaveDB(StockDB.dtFolderAll); } if (StockDB.dtFolderRelChanged) { StockDB.SaveDB(StockDB.dtFolderRel); } }