C# Signature:

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

VB Signature:

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

User-Defined Types:

None.

Change Notes:

- Changed IntPtr to UIntPtr:

  When invoking with IntPtr for the handles, you will run into an Overflow. UIntPtr is the right choice.

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:

Microsoft.Win32.Registry.BaseKeyName.OpenSubKey("[KeyName]")

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