how to access registry

[shethashish_a]

Hi,
I am a VB developer and I want to know how to access registry values in windows? how to write to the registry?
I want to access name of some application's installed on the user's pc so how to do that using registry? Or any other way to do that?

Also while installing our application how can we make the user to enter his or his company name and how can we access that name in our application?

Can any body help me?

Thanks,
Ashish

[adnankhan]

Look in MSDN for help on the following WIN32 APIs.

RegOpenKey, RegCloseKey etc ...

Here is some code to help you out ...

// QueryKey - enumerates the subkeys of a given key and the associated
// values and then copies the information about the keys and values
// into a pair of edit controls and list boxes.
// hDlg - dialog box that contains the edit controls and list boxes
// hKey - key whose subkeys and values are to be enumerated

VOID QueryKey(HWND hDlg, HANDLE hKey)
{
CHAR achKey[MAX_PATH];
CHAR achClass[MAX_PATH] = ""; // buffer for class name
DWORD cchClassName = MAX_PATH; // length of class string
DWORD cSubKeys; // number of subkeys
DWORD cbMaxSubKey; // longest subkey size
DWORD cchMaxClass; // longest class string
DWORD cValues; // number of values for key
DWORD cchMaxValue; // longest value name
DWORD cbMaxValueData; // longest value data
DWORD cbSecurityDescriptor; // size of security descriptor
FILETIME ftLastWriteTime; // last write time

DWORD i, j;
DWORD retCode, retValue;

CHAR achValue[MAX_VALUE_NAME];
DWORD cchValue = MAX_VALUE_NAME;
CHAR achBuff[80];

// Get the class name and the value count.
RegQueryInfoKey(hKey, // key handle
achClass, // buffer for class name
&cchClassName, // length of class string
NULL, // reserved
&cSubKeys, // number of subkeys
&cbMaxSubKey, // longest subkey size
&cchMaxClass, // longest class string
&cValues, // number of values for this key
&cchMaxValue, // longest value name
&cbMaxValueData, // longest value data
&cbSecurityDescriptor, // security descriptor
&ftLastWriteTime); // last write time

SetDlgItemText(hDlg, IDE_CLASS, achClass);
SetDlgItemInt(hDlg, IDE_CVALUES, cValues, FALSE);

SendMessage(GetDlgItem(hDlg, IDL_LISTBOX),
LB_ADDSTRING, 0, (LONG) "..");

// Enumerate the child keys, until RegEnumKeyEx fails. Then
// get the name of each child key and copy it into the list box.

SetCursor(LoadCursor(NULL, IDC_WAIT));
for (i = 0, retCode = ERROR_SUCCESS;
retCode == ERROR_SUCCESS; i++)
{
retCode = RegEnumKeyEx(hKey,
i,
achKey,
MAX_PATH,
NULL,
NULL,
NULL,
&ftLastWriteTime);
if (retCode == (DWORD)ERROR_SUCCESS)
{
SendMessage(GetDlgItem(hDlg, IDL_LISTBOX),
LB_ADDSTRING, 0, (LONG) achKey);
}
}
SetCursor(LoadCursor (NULL, IDC_ARROW));

// Enumerate the key values.
SetCursor(LoadCursor(NULL, IDC_WAIT));

if (cValues)
{
for (j = 0, retValue = ERROR_SUCCESS;
j < cValues; j++)
{
cchValue = MAX_VALUE_NAME;
achValue[0] = '\0';
retValue = RegEnumValue(hKey, j, achValue,
&cchValue,
NULL,
NULL, // &dwType,
NULL, // &bData,
NULL); // &bcData

if (retValue != (DWORD) ERROR_SUCCESS &&
retValue != ERROR_INSUFFICIENT_BUFFER)
{
wsprintf (achBuff,
"Line:%d 0 based index = %d, retValue = %d, "
"ValueLen = %d",
__LINE__, j, retValue, cchValue);
MessageBox (hDlg, achBuff, "Debug", MB_OK);
}

achBuff[0] = '\0';

// Add each value to a list box.
if (!lstrlen(achValue))
lstrcpy(achValue, "<NO NAME>");
wsprintf(achBuff, "%d) %s ", j, achValue);
SendMessage(GetDlgItem(hDlg,IDL_LISTBOX2),
LB_ADDSTRING, 0, (LONG) achBuff);
}

SetCursor(LoadCursor(NULL, IDC_ARROW));
}


Hope this helps

Take it easy
AK