RegOpenKeyEx---Deleting a Key with Subkeys

The example in this topic uses the RegOpenKeyEx, RegEnumKeyEx, and RegDeleteKey functions to delete a registry key with subkeys.

To test this example, create the following registry key by using Regedt32.exe, and then add a few values and subkeys:

HKEY_CURRENT_USER\Software\TestDir

After running the code, use the F5 key to refresh the registry data, and notice that theTestDir key is deleted.

#include <windows.h>#include <stdio.h>#include <strsafe.h>//*************************************************************////  RegDelnodeRecurse()////  Purpose:    Deletes a registry key and all its subkeys / values.////  Parameters: hKeyRoot    -   Root key//              lpSubKey    -   SubKey to delete////  Return:     TRUE if successful.//              FALSE if an error occurs.////*************************************************************BOOL RegDelnodeRecurse (HKEY hKeyRoot, LPTSTR lpSubKey){    LPTSTR lpEnd;    LONG lResult;    DWORD dwSize;    TCHAR szName[MAX_PATH];    HKEY hKey;    FILETIME ftWrite;    // First, see if we can delete the key without having    // to recurse.    lResult = RegDeleteKey(hKeyRoot, lpSubKey);    if (lResult == ERROR_SUCCESS)         return TRUE;    lResult = RegOpenKeyEx (hKeyRoot, lpSubKey, 0, KEY_READ, &hKey);    if (lResult != ERROR_SUCCESS)     {        if (lResult == ERROR_FILE_NOT_FOUND) {            printf("Key not found.\n");            return TRUE;        }         else {            printf("Error opening key.\n");            return FALSE;        }    }    // Check for an ending slash and add one if it is missing.    lpEnd = lpSubKey + lstrlen(lpSubKey);    if (*(lpEnd - 1) != TEXT('\\'))     {        *lpEnd =  TEXT('\\');        lpEnd++;        *lpEnd =  TEXT('\0');    }    // Enumerate the keys    dwSize = MAX_PATH;    lResult = RegEnumKeyEx(hKey, 0, szName, &dwSize, NULL,                           NULL, NULL, &ftWrite);    if (lResult == ERROR_SUCCESS)     {        do {            StringCchCopy (lpEnd, MAX_PATH*2, szName);            if (!RegDelnodeRecurse(hKeyRoot, lpSubKey)) {                break;            }            dwSize = MAX_PATH;            lResult = RegEnumKeyEx(hKey, 0, szName, &dwSize, NULL,                                   NULL, NULL, &ftWrite);        } while (lResult == ERROR_SUCCESS);    }    lpEnd--;    *lpEnd = TEXT('\0');    RegCloseKey (hKey);    // Try again to delete the key.    lResult = RegDeleteKey(hKeyRoot, lpSubKey);    if (lResult == ERROR_SUCCESS)         return TRUE;    return FALSE;}//*************************************************************////  RegDelnode()////  Purpose:    Deletes a registry key and all its subkeys / values.////  Parameters: hKeyRoot    -   Root key//              lpSubKey    -   SubKey to delete////  Return:     TRUE if successful.//              FALSE if an error occurs.////*************************************************************BOOL RegDelnode (HKEY hKeyRoot, LPTSTR lpSubKey){    TCHAR szDelKey[MAX_PATH*2];    StringCchCopy (szDelKey, MAX_PATH*2, lpSubKey);    return RegDelnodeRecurse(hKeyRoot, szDelKey);}void __cdecl main(){   BOOL bSuccess;   bSuccess = RegDelnode(HKEY_CURRENT_USER, TEXT("Software\\TestDir"));   if(bSuccess)      printf("Success!\n");   else printf("Failure.\n");}