Q258528: HOWTO: Read a REG_MULTI_SZ From the Registry
Article: Q258528
Product(s): Microsoft FoxPro
Version(s): 3.0,3.0b,5.0,5.0a,6.0
Operating System(s):
Keyword(s): kbAPI kbvfp300 kbvfp300b kbvfp500 kbvfp500a kbvfp600 kbGrpDSFox kbDSupport kbCodeSnippe
Last Modified: 11-JUN-2002
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The information in this article applies to:
- Microsoft Visual FoxPro for Windows, versions 3.0, 3.0b, 5.0, 5.0a, 6.0
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SUMMARY
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This article shows how to read a REG_MULTI_SZ value from the registry.
MORE INFORMATION
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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:
Q256986 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:
HKEY_LOCAL_MACHINE\Software
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
Line2
Line3
Line4
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
nKey = HKEY_LOCAL_MACHINE
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)
ENDFOR
ELSE
=MESSAGEBOX("Function Not Successful.")
ENDIF
FUNCTION ReadREG_MULTI_SZ
* 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
ENDIF
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)
=RegCloseKey(nKeyHandle)
IF (nErrCode # 0) THEN
RETURN 0
ENDIF
* 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
ELSE
lNotDone = .F.
ENDIF
ENDDO
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.
REFERENCES
==========
For additional information obtaining values from the registry, click the article
number below to view the article in the Microsoft Knowledge Base:
Q244675 HOWTO:Use Windows Script Host to Read, Write, Delete Registry
Additional query words:
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Keywords : kbAPI kbvfp300 kbvfp300b kbvfp500 kbvfp500a kbvfp600 kbGrpDSFox kbDSupport kbCodeSnippet
Technology : kbVFPsearch kbAudDeveloper kbVFP300 kbVFP300b kbVFP500 kbVFP600 kbVFP500a
Version : :3.0,3.0b,5.0,5.0a,6.0
Issue type : kbhowto
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