C# Signature:

[DllImport("advapi32.dll", CharSet = CharSet.Unicode, EntryPoint = "RegOpenKeyEx")]
static extern int RegOpenKeyEx(
    IntPtr hKey,
    string subKey,
    uint options,
    int sam,
    out IntPtr phkResult );

VB Signature:

Declare Function RegOpenKeyEx Lib "advapi32.dll"  Alias "RegOpenKeyExA"(ByVal hKey As Integer, ByVal lpSubKey As String, ByVal ulOptions As Integer, ByVal samDesired As Integer, ByRef phkResult As Integer) As Integer

User-Defined Types:

None.

Notes:

If the function fails, the return value is a nonzero error code defined in Winerror.h. You can use the FormatMessage function with the FORMAT_MESSAGE_FROM_SYSTEM flag to get a generic description of the error.

uint options: reserved, must be zero.

int sam: access mask that specifies the desired access rights to the key.

values for sam:

Const KEY_QUERY_VALUE = &H1

Const KEY_SET_VALUE = &H2

Const KEY_CREATE_SUB_KEY = &H4

Const KEY_ENUMERATE_SUB_KEYS = &H8

Const KEY_NOTIFY = &H10

Const KEY_CREATE_LINK = &H20

Const KEY_WOW64_32KEY = &H200

Const KEY_WOW64_64KEY = &H100

Const KEY_WOW64_RES = &H300

For compatibility with 16-bit versions of Windows only 'RegOpenKey' is available.

Tips & Tricks:

Please add some!!

Sample Code:

Please add some!!

Alternative Managed API:

Do you know one? Please contribute it!

Please edit this page!

Do you have...

• helpful tips or sample code to share for using this API in managed code?
• corrections to the existing content?
• variations of the signature you want to share?
• additional languages you want to include?

Select "Edit This Page" on the right hand toolbar and edit it! Or add new pages containing supporting types needed for this API (structures, delegates, and more).