How to check if a registry value exists using C

Question

How to check if a registry value exists by C  code  This is my code  I want to check if  Start  exists   public static bool checkMachineType         RegistryKey winLogonKey   Registry LocalMachine OpenSubKey   System CurrentControlSet services pcmcia   true       string currentKey  winLogonKey GetValue  Start   ToString         if  currentKey     0           return  false       return  true

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public static bool RegistryValueExists string hive HKLM or HKCU  string registryRoot  string valueName        RegistryKey root      switch  hive HKLM or HKCU ToUpper                  case  HKLM               root   Registry LocalMachine OpenSubKey registryRoot  false               break          case  HKCU               root   Registry CurrentUser OpenSubKey registryRoot  false               break          default              throw new System InvalidOperationException  parameter registryRoot must be either   HKLM   or   HKCU                 return root GetValue valueName     null

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For Registry Key you can check if it is null after getting it  It will be  if it doesn t exist   For Registry Value you can get names of Values for the current key and check if this array contains the needed Value name   Example   public static bool checkMachineType             RegistryKey winLogonKey   Registry LocalMachine OpenSubKey   System CurrentControlSet services pcmcia   true       return  winLogonKey GetValueNames   Contains  Start

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internal static Func lt string  string  bool gt  regKey   delegate  string KeyLocation  string Value                           get registry key with Microsoft Win32 Registrys             RegistryKey rk    RegistryKey Registry GetValue KeyLocation  Value  null      KeyLocation and Value variables from method  null object because no default value is present  Must be casted to RegistryKey because method returns object              if   rk     null     if the RegistryKey is null which means it does not exist                                  the key does not exist                 return false     return false because it does not exist                              the registry key does exist             return true     return true because it does exist              usage              usage             Create Key - while  loading                        RegistryKey k              k   Registry CurrentUser CreateSubKey  stuff                k SetValue  value    value                Thread Sleep int MaxValue                 no need to k close because exiting control              if  regKey   HKEY CURRENT USER stuff           value                              key exists              return                       key does not exist

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string keyName   HKEY LOCAL MACHINE System CurrentControlSet services pcmcia   string valueName  Start   if  Registry GetValue keyName  valueName  null     null           code if key Not Exist   else          code if key Exist

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Of course   Fagner Antunes Dornelles  is correct in its answer  But it seems to me that it is worth checking the registry branch itself in addition  or be sure of the part that is exactly there   For example   dirty hack    i need to establish trust in the RMS infrastructure  otherwise when i open Word or Excel documents  i will be prompted for  Active Directory Rights Management Services   Here s how i can add remote trust to me servers in the enterprise infrastructure   foreach  var strServer in listServer        try               RegistryKey regCurrentUser   Registry CurrentUser OpenSubKey   Software  Classes  Local Settings  Software  Microsoft  MSIPC   strServer    false           if  regCurrentUser    null              throw new ApplicationException  Not found registry SubKey                if  regCurrentUser GetValueNames   Contains  UserConsent      false              throw new ApplicationException  Not found value in SubKey                  catch  ApplicationException appEx                Console WriteLine appEx           try                       RegistryKey regCurrentUser   Registry CurrentUser OpenSubKey   Software  Classes  Local Settings  Software  Microsoft  MSIPC   true               RegistryKey newKey   regCurrentUser CreateSubKey strServer  true               newKey SetValue  UserConsent   1  RegistryValueKind DWord                     catch Exception ex                        Console WriteLine    ex  Pipec kakoito

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RegistryKey rkSubKey   Registry CurrentUser OpenSubKey   Your Registry Key Location   false           if  rkSubKey    null                          It doesn t exist                   else                         It exists and do something if you want to

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public bool ValueExists RegistryKey Key  string Value       try             return Key GetValue Value     null          catch             return false           This simple function will return true only if a value is found but it is not null  else will return false if the value exists but it is null or the value doesn t exists in the key     USAGE for your question   if  ValueExists winLogonKey   Start            The values exists   else          The values does not exists

[c#] How to check if a registry value exists using C#?

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