| #include <shellapi.h> |
| LONG RegOpenKey(hkey, lpszSubKey, lphkResult) | |||||
| HKEY hkey; | /* handle of an open key | */ | |||
| LPCSTR lpszSubKey; | /* address of string for subkey to open | */ | |||
| HKEY FAR* lphkResult; | /* address of handle of open key | */ | |||
The RegOpenKey function opens the specified key.
hkey
Identifies an open key (which can be HKEY_CLASSES_ROOT). The key opened by the RegOpenKey function is a subkey of the key identified by this parameter. This value should not be NULL.
lpszSubKey
Points to a null-terminated string specifying the name of the subkey to open.
lphkResult
Points to the handle of the key that is opened.
The return value is ERROR_SUCCESS if the function is successful. Otherwise, it is an error value.
Unlike the RegCreateKey function, the RegOpenKey function does not create the specified key if the key does not exist in the database.
The following example uses the RegOpenKey function to retrieve the handle of the StdFileEditing subkey, calls the RegQueryValue function to retrieve the name of an object handler, and then calls the RegDeleteKey function to delete the key if its value is nwappobj.dll:
char szBuff[80];
LONG cb;
HKEY hkStdFileEditing;
if (RegOpenKey(HKEY_CLASSES_ROOT,
"NewAppDocument\\protocol\\StdFileEditing",
&hkStdFileEditing) == ERROR_SUCCESS) {
cb = sizeof(szBuff);
if (RegQueryValue(hkStdFileEditing,
"handler",
szBuff,
&cb) == ERROR_SUCCESS
&& lstrcmpi("nwappobj.dll", szBuff) == 0)
RegDeleteKey(hkStdFileEditing, "handler");
RegCloseKey(hkStdFileEditing);
}