private static void IOHelperTest() { Stream stream = IOHelper.FileToStream(@"E:\allTravelConsultant.txt"); IOHelper.StreamToFile(stream, @"E:\test.txt"); byte[] bytes = IOHelper.ConvertStreamToBytes(stream); string base64Str = IOHelper.ConvertBytesToBase64Str(bytes); IOHelper.WriteContentIntoTxt(new List <string> { base64Str }, @"E:\test.txt", false); List <string> res = IOHelper.ReadContentFromTxt(@"E:\test.txt"); }