C# Signature:

/// <summary> The RegEnumKeyEx function enumerates subkeys of the specified open registry key. </summary>
/// <param name="hkey"> Handle to an open key. </param>
/// <param name="index"> Index of the subkey to retrieve. </param>
/// <param name="lpName"> Pointer to a buffer that receives the name of the subkey. </param>
/// <param name="lpcbName"> Pointer to a variable that specifies the size of the buffer specified by the lpname parameter. </param>
/// <param name="reserved"> Reserved; must be NULL. </param>
/// <param name="lpClass"> Pointer to a buffer that receives the null-terminated class string of the enumerated subkey. </param>
/// <param name="lpcbClass"> Pointer to a variable that specifies the size of the buffer specified by the lpClass parameter. </param>
/// <param name="lpftLastWriteTime"> Pointer to a variable that receives the time at which the enumerated subkey was last written. </param>
/// <returns> If the function succeeds, the return value is ERROR_SUCCESS (0). </returns>
[DllImport("advapi32.dll", EntryPoint = "RegEnumKeyEx")]
extern private static int RegEnumKeyEx(UIntPtr hkey, uint index, StringBuilder lpName, ref uint lpcbName,
    IntPtr reserved, IntPtr lpClass, IntPtr lpcbClass, out long lpftLastWriteTime);

VB Signature:

Declare Auto Function RegEnumKeyEx Lib "Advapi32" ( _
   ByVal hKey As IntPtr, _
   ByVal dwIndex As Integer, _
   ByVal lpName As StringBuilder, _
   ByRef lpcName As Integer, _
   ByVal lpReserved As IntPtr, _
   ByVal lpClass As IntPtr, _
   ByVal lpcClass As IntPtr, _
   ByVal lpftLastWriteTime As IntPtr _
) As Integer

User-Defined Types:

None.

Alternative Managed API:

Do you know one? Please contribute it!

Notes:

LONG RegEnumKeyEx(
   HKEY hKey,
   DWORD dwIndex,
   LPTSTR lpName,
   LPDWORD lpcName,
   LPDWORD lpReserved,
   LPTSTR lpClass,
   LPDWORD lpcClass,
   PFILETIME lpftLastWriteTime
);

Tips & Tricks:

Please add some!

Sample Code:

Public Function GetSubKeyNames() As String()
   Dim i, ret, NameSize As Integer
   Dim sc As New StringCollection
   Dim sb As New StringBuilder(MAX_REG_KEYNAME_SIZE + 1)
   Dim ans(-1) As String

   ' quick sanity check
   If hKey.Equals(IntPtr.Zero) Then
     Throw New ApplicationException("Cannot access a closed registry key")
   End If

   Do
     NameSize = MAX_REG_KEYNAME_SIZE + 1
     ret = RegEnumKeyEx(hKey, i, sb, NameSize, IntPtr.Zero, IntPtr.Zero, IntPtr.Zero, IntPtr.Zero)
     If ret <> 0 Then
       Exit Do
     End If
     sc.Add(sb.ToString)
     i += 1
   Loop

   If sc.Count > 0 Then
     ReDim ans(sc.Count - 1)
     sc.CopyTo(ans, 0)
   End If
   Return ans
End Function