public class AppConfigs
{
 private static Lazy<AppConfigs> instance = new Lazy<AppConfigs>(() => new AppConfigs());
 public static AppConfigs Instance = instance.Value;

 private readonly Dictionary<string, Dictionary<string, string>> keyValuePairs = new Dictionary<string, Dictionary<string, string>>();
 private readonly static string configPath = Path.Combine(System.Windows.Forms.Application.StartupPath, "Config", "设置");
 private AppConfigs()
 {

 }

 /// <summary>
 /// 添加config文件
 /// </summary>
 /// <param name="configName"></param>
 public static void AddConfig(string configName)
 {
     if (!Directory.Exists(configPath))
     {
         Directory.CreateDirectory(configPath);
     }
     using (var scope = new TransactionScope())
     {
         FileStream newfile = null;
         if (!File.Exists(configName))
         {
             newfile = new FileStream(configName, FileMode.Create, FileAccess.Write, FileShare.ReadWrite, 8, FileOptions.WriteThrough);
         }
         else
         {
             newfile = new FileStream(configName, FileMode.Truncate, FileAccess.Write, FileShare.ReadWrite, 8, FileOptions.WriteThrough);
         }
         var sw = new StreamWriter(newfile);
         string s = "<?xml version=\"1.0\" encoding=\"utf-8\"?>" + "\n" + "<configuration>" + "\n" + "<appSettings> " + "\n" + " </appSettings>" + "\n" + "</configuration>";
         sw.Write(s);
         sw.Close();
         newfile.Close();
         scope.Complete();
     }
 }

 /// <summary>
 /// 获取config文件参数
 /// </summary>
 /// <param name="configName"></param>
 /// <param name="key"></param>
 /// <param name="val"></param>
 /// <returns></returns>
 public string GetConfig(string configName, string key, string val = "0")
 {
     key = AesEncrypt(key);//加密
     string path = Path.Combine(configPath, configName);
     if (keyValuePairs.TryGetValue(configName, out var keyValues))
     {
         if (keyValues.TryGetValue(key, out var value))
         {
             return value;
         }
     }
     if (File.Exists(path))
     {
         //判断是否需要备份文件
         ConfigBackup.GetBackupFile(path);

         var ecf = new ExeConfigurationFileMap
         {
             ExeConfigFilename = path
         };
         Configuration config = ConfigurationManager.OpenMappedExeConfiguration(ecf, ConfigurationUserLevel.None);
         var keys = config.AppSettings.Settings.AllKeys.ToList();
         if (keys == null || keys.Count == 0)
             return val;
         if (keys.Contains(key))
         {
             val = AesDecrypt(config.AppSettings.Settings[key].Value.ToString());//解密
         }
         else
         {
             string AESval = AesEncrypt(val);//加密
             config.AppSettings.Settings.Add(key, AESval);
             config.Save(ConfigurationSaveMode.Modified);
         }
         var pairs = new Dictionary<string, string>();
         foreach (var item in keys)
         {
             pairs.Add(item.ToString(), AesDecrypt(config.AppSettings.Settings[item.ToString()].Value.ToString()));
         }
         if (keyValuePairs.ContainsKey(configName))
         {
             keyValuePairs[configName] = pairs;
         }
         else
         {
             keyValuePairs.Add(configName, pairs);
         }
     }
     else
     {
         if (!File.Exists(path)) AddConfig(path);
         var ecf = new ExeConfigurationFileMap
         {
             ExeConfigFilename = path
         };
         Configuration config = ConfigurationManager.OpenMappedExeConfiguration(ecf, ConfigurationUserLevel.None);
         string AESval = AesEncrypt(val);//加密
         config.AppSettings.Settings.Add(key, AESval);
         config.Save(ConfigurationSaveMode.Modified);
     }
     if (!keyValuePairs.ContainsKey(configName))
     {
         var pair = new Dictionary<string, string>
         {
             { key, val }
         };
         keyValuePairs.Add(configName, pair);
     }
     else if (keyValuePairs.ContainsKey(configName))
     {
         if (!keyValuePairs[configName].ContainsKey(key))
         {
             keyValuePairs[configName].Add(key, val);
         }
     }
     return val;
 }

 /// <summary>
 /// 设置config文件参数
 /// </summary>
 /// <param name="configName"></param>
 /// <param name="key"></param>
 /// <param name="value"></param>
 public void SetConfig(string configName, string key, string value = "1")
 {
     string path = Path.Combine(configPath, configName);
     string AESval = AesEncrypt(value);//加密
     key = AesEncrypt(key);//加密
     if (keyValuePairs.ContainsKey(configName) && keyValuePairs[configName].ContainsKey(key))
     {
         if (keyValuePairs[configName][key] == value)
             return;
     }
     //备份
     ConfigBackup.CopyFile(path);

     if (File.Exists(path))
     {
         var ecf = new ExeConfigurationFileMap
         {
             ExeConfigFilename = path
         };
         Configuration config = ConfigurationManager.OpenMappedExeConfiguration(ecf, ConfigurationUserLevel.None);

         if (config.AppSettings.Settings[key] != null)
         {
             config.AppSettings.Settings[key].Value = AESval;
         }
         else
         {
             config.AppSettings.Settings.Add(key, AESval);
         }
         config.Save(ConfigurationSaveMode.Modified);
     }
     else
     {
         if (!File.Exists(path)) AddConfig(path);
         var ecf = new ExeConfigurationFileMap
         {
             ExeConfigFilename = path
         };
         Configuration config = ConfigurationManager.OpenMappedExeConfiguration(ecf, ConfigurationUserLevel.None);
         config.AppSettings.Settings.Add(key, AESval);
         config.Save(ConfigurationSaveMode.Modified);
     }
     if (!keyValuePairs.ContainsKey(configName))
     {
         var pair = new Dictionary<string, string>
         {
             { key, value }
         };
         keyValuePairs.Add(configName, pair);
     }
     else if (keyValuePairs.ContainsKey(configName))
     {
         if (!keyValuePairs[configName].ContainsKey(key))
         {
             keyValuePairs[configName].Add(key, value);
         }
         else
         {
             keyValuePairs[configName][key] = value;
         }
     }
     ConfigurationManager.RefreshSection("appSettings");
 }

 private readonly string key = "niubiultruplus++";//必须16位
 /// <summary>
 ///  AES 加密
 /// </summary>
 /// <param name="str">明文（待加密）</param>
 /// <returns></returns>
 public string AesEncrypt(string str)
 {
     if (string.IsNullOrEmpty(str)) return null;
     Byte[] toEncryptArray = Encoding.UTF8.GetBytes(str);

     var rm = new RijndaelManaged
     {
         Key = Encoding.UTF8.GetBytes(key),
         Mode = CipherMode.ECB,
         Padding = PaddingMode.PKCS7
     };

     ICryptoTransform cTransform = rm.CreateEncryptor();
     Byte[] resultArray = cTransform.TransformFinalBlock(toEncryptArray, 0, toEncryptArray.Length);

     return Convert.ToBase64String(resultArray, 0, resultArray.Length);
 }
 /// <summary>
 ///  AES 解密
 /// </summary>
 /// <param name="str">明文（待解密）</param>
 /// <returns></returns>
 public string AesDecrypt(string str)
 {
     if (string.IsNullOrEmpty(str)) return null;
     Byte[] toEncryptArray = Convert.FromBase64String(str);

     var rm = new RijndaelManaged
     {
         Key = Encoding.UTF8.GetBytes(key),
         Mode = CipherMode.ECB,
         Padding = PaddingMode.PKCS7
     };

     ICryptoTransform cTransform = rm.CreateDecryptor();
     Byte[] resultArray = cTransform.TransformFinalBlock(toEncryptArray, 0, toEncryptArray.Length);
     return Encoding.UTF8.GetString(resultArray);
 }

}