How To Read a REG_MULTI_SZ From the Registry

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Article ID: 258528 - View products that this article applies to.
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This article shows how to read a REG_MULTI_SZ value from the registry.


NOTE: This article requires regedt32.exe, which is only available on Microsoft Windows NT and Microsoft Windows 2000, to add the test key and value. The code included runs on Windows 9X with an existing REG_MULTI_SZ value.

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 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.

NOTE: This article uses a registry key that is created just for testing and should be deleted when you are finished.
  1. Start Registry Editor (Regedt32.exe).
  2. Locate the following key in the registry:
  3. On the Edit menu, click Add Key, and then add the following registry Key:
       Key Name:   VfpRegTest
  4. Click on the Key added in step 3. On the Edit menu, click Add Value, and then add the following value:
       Value Name: TestREG_MULTI_SZ
       Data Type:  REG_MULTI_SZ
       Value:      Line1
       Be sure to press the Enter key after each line.
  5. Quit Registry Editor.
  6. From Visual FoxPro, create a program and enter the following code:
    *Start of Code
    #DEFINE HKEY_LOCAL_MACHINE   -2147483646
    LOCAL nKey, cSubKey, cValue, nStrings, acValueRead, nLoopVar
    cSubKey = "Software\VfpRegTest"
    cValue = "TestREG_MULTI_SZ"
    nStrings = ReadREG_MULTI_SZ(nKey, cSubKey, cValue, @acValueRead)
    IF (nStrings > 0) THEN
       =MESSAGEBOX("Function Successful.")
       FOR nLoopVar = 1 TO nStrings
          ? acValueRead(nLoopVar)
       =MESSAGEBOX("Function Not Successful.")
    * This function reads a REG_MULTI_SZ value from the registry. It will return
    * the number of Elements in acValueRead if successful and store the 
    * strings in acValueRead. If not successful, it will return 0 and 
    * acValueRead will contain 0 elements
       PARAMETERS  nKey, cSubKey, cValue,  acValueRead
       * 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.
       * cValue The value that is going to be read.
       * acValueRead Array of strings read from the registry.
       * Constants that are needed for Registry functions
       #DEFINE REG_MULTI_SZ                 7
       * WIN 32 API functions that are used
       DECLARE Integer RegOpenKey IN Win32API ;
          Integer nHKey, String @cSubKey, Integer @nResult
       DECLARE Integer RegQueryValueEx IN Win32API ;
          Integer nHKey, String lpszValueName, Integer dwReserved,;
          Integer @lpdwType, String @lpbData, Integer @lpcbData
       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
       LOCAL lNotDone      && Used to Exit Loop
       LOCAL nOccurance    && The occurrence of CHR(0) in the string
       LOCAL nPrevPos      && Previous element in Array 
       LOCAL nCurrPos      && Current element in Array being processed
       LOCAL nElements     && Number of Elements in the Array
       * Initialize the variables
       nKeyHandle = 0
       lpdwReserved = 0           
       lpdwValueType = REG_MULTI_SZ
       lNotDone = .T.
       nOccurance = 1
       nPrevPos = 1
       nElements = 0
       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 0
       lpbValue = ""
       lpcbValueSize = 1 
       * Get the size of the data in the value
       nErrCode=RegQueryValueEx(nKeyHandle, cValue, lpdwReserved, @lpdwValueType, @lpbValue, @lpcbValueSize)
       * Make the buffer big enough
       lpbValue = SPACE(lpcbValueSize)   
       nErrCode=RegQueryValueEx(nKeyHandle, cValue, lpdwReserved, @lpdwValueType, @lpbValue, @lpcbValueSize)
       IF (nErrCode # 0) THEN
          RETURN 0
       * This loop fills an array with the strings stored in the registry
       DO WHILE lNotDone
          nCurrPos = AT(CHR(0), lpbValue, nOccurance)  && CHR(0) is used to separate lines in the registry
          IF ((nCurrPos > 0) AND (nCurrPos < lpcbValueSize)) THEN
             nElements = nElements + 1
             DIMENSION acValueRead(nElements)
             acValueRead(nElements) = SUBSTR(lpbValue, nPrevPos, nCurrPos - nPrevPos)
             nPrevPos = nCurrPos + 1
             nOccurance = nOccurance + 1
             lNotDone = .F.
    RETURN nElements
    * End of Code
  7. Run the program created in step 6. A message box appears saying "Function Successful" and the values appear on the desktop.
  8. You can replace nKey, cSubKey, and cValue with your information to be read from the registry.
(c) Microsoft Corporation 2000, All Rights Reserved. Contributions by Mark Barnard, Microsoft Corporation.


For additional information obtaining values from the registry, click the article number below to view the article in the Microsoft Knowledge Base:
244675 How ToUse Windows Script Host to Read, Write, Delete Registry


Article ID: 258528 - Last Review: July 1, 2004 - Revision: 2.2
  • Microsoft Visual FoxPro 3.0 Standard Edition
  • Microsoft Visual FoxPro 3.0b Standard Edition
  • Microsoft Visual FoxPro 5.0 Standard Edition
  • Microsoft Visual FoxPro 5.0a
  • Microsoft Visual FoxPro 6.0 Professional Edition
kbapi kbcodesnippet kbhowto KB258528

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