Article ID: 258559 - Last Review: July 15, 2004 - Revision: 2.2

How To Write a REG_SZ Value to the Registry

View products that this article applies to.

This article was previously published under Q258559

SUMMARY

This article shows how to write a REG_SZ value to the registry.

IMPORTANT: This article contains information about modifying the registry. Before you modify the registry, make sure to back it up and make sure that you understand how to restore the registry if a problem occurs. For information about how to back up, restore, and edit the registry, click the following article number to view the article in the Microsoft Knowledge Base:

256986 (http://support.microsoft.com/kb/256986/EN-US/ ) Description of the Microsoft Windows Registry

WARNING: If you use Registry Editor incorrectly, you may cause serious problems that may require you to reinstall your operating system. Microsoft cannot guarantee that you can solve problems that result from using Registry Editor incorrectly. Use Registry Editor at your own risk.

This information about the Registry Editor in this article is for Microsoft Windows NT and Microsoft Windows 2000. If you are running Microsoft Windows 95 or Microsoft Windows 98, you need to use the Regedit.exe file instead of the Regedt32.exe file.

NOTE: This article uses a registry key that is created just for testing and should be deleted when you are finished.

Start Registry Editor (Regedt32.exe).
Locate the following key in the registry:
HKEY_LOCAL_MACHINE\Software
On the Edit menu, click Add Key, and then add the following registry key:
Key Name: VfpRegTest
Click on the registry key added in step 3. On the Edit menu, click Add Value, and then add the following value:
Value Name: TestREG_SZ Data Type: REG_SZ Value: None
Quit Registry Editor.

From Visual FoxPro, create a program and enter the following code:

*Start of Code
#DEFINE HKEY_LOCAL_MACHINE          -2147483646

LOCAL nKey, cSubKey, cValue, lSuccess, cValueToWrite
nKey = HKEY_LOCAL_MACHINE
cSubKey = "Software\VfpRegTest"
cValue = "TestREG_SZ"
cValueToWrite = "This is a String."

lSuccess = WriteREG_SZ(nKey, cSubKey, cValue, cValueToWrite)
IF (lSuccess) THEN
   =MESSAGEBOX("Function Successful.")
ELSE
   =MESSAGEBOX("Function Not Successful.")
ENDIF

FUNCTION WriteREG_SZ
* This function writes a REG_SZ value to the registry. If successful,
* its will return .T.. If not successful, it will return .F..
   PARAMETERS  nKey, cSubKey, cValue, cValueToWrite
   * nKey The root key to open. It can be any of the constants defined below
   *#DEFINE HKEY_CLASSES_ROOT           -2147483648
   *#DEFINE HKEY_CURRENT_USER           -2147483647
   *#DEFINE HKEY_LOCAL_MACHINE          -2147483646
   *#DEFINE HKEY_USERS                  -2147483645
   * cSubKey The SubKey to open.
   * cValueToWrite The value being written to the registry.

   * Constants that are needed for Registry functions
   #DEFINE REG_SZ   1

   * WIN 32 API functions that are used
   DECLARE Integer RegOpenKey IN Win32API ;
      Integer nHKey, String @cSubKey, Integer @nResult
   DECLARE Integer RegSetValueEx IN Win32API ;
      Integer hKey, String lpszValueName, Integer dwReserved,;
      Integer fdwType, String lpbData, Integer cbData
   DECLARE Integer RegCloseKey IN Win32API Integer nHKey

   * Local variables used
   LOCAL nErrCode      && Error Code returned from Registry functions
   LOCAL nKeyHandle    && Handle to Key that is opened in the Registry
   LOCAL lpdwValueType && Type of Value that we are looking for
   LOCAL lpbValue      && The data stored in the value
   LOCAL lpcbValueSize && Size of the variable
   LOCAL lpdwReserved  && Reserved Must be 0
    
   * Initialize the variables
   nKeyHandle = 0
   lpdwReserved = 0           
   lpdwValueType = REG_SZ
   lpbValue = cValueToWrite
   
   nErrCode = RegOpenKey(nKey, cSubKey, @nKeyHandle)
   * If the error code isn't 0, then the key doesn't exist or can't be opened.
   IF (nErrCode # 0) THEN
      RETURN .F.
   ENDIF

   lpcbValueSize = LEN(lpbValue)   && Store the length of the string
   nErrCode=RegSetValueEx(nKeyHandle, cValue, lpdwReserved, lpdwValueType, lpbValue, lpcbValueSize)
   
   =RegCloseKey(nKeyHandle)
   IF (nErrCode # 0) THEN
      RETURN .F.
   ENDIF
RETURN .T.
* End of Code

Run the program created in step 6. A message box appears indicating "Function Successful."
You can replace nKey, cSubKey, cValue, and cValueToWrite with your information to be written to the registry.