C# Signature:

[DllImport("advapi32.dll", CharSet=CharSet.Auto)]
static extern uint SetNamedSecurityInfo(
    string pObjectName,
    SE_OBJECT_TYPE ObjectType,
    SECURITY_INFORMATION SecurityInfo,
    IntPtr psidOwner,
    IntPtr psidGroup,
    IntPtr pDacl,
    IntPtr pSacl);

VB Signature:

Declare Function SetNamedSecurityInfo Lib "advapi32.dll" ( _
    ByVal pObjectName As String, _
    ByVal ObjectType As Integer, _
    ByVal SecurityInfo As Integer, _
    ByVal psidOwner As IntPtr, _
    ByVal psidGroup As IntPtr, _
    ByVal pDacl As IntPtr, _
    ByVal pSacl As IntPtr) As Integer

User-Defined Types:

None.

Notes:

Tips & Tricks:

Please add some!

C# Sample Code:

Please add some!

VB.Net Sample Code:

    ' Type of Securable Object we are operating in this sample code
    Private Const SE_FILE_OBJECT = 1&

    ' The Security Information constants required
    Private Const DACL_SECURITY_INFORMATION = 4&

    Dim pSecDesc, pNewDACL, pOldDACL As IntPtr
    Dim ea As EXPLICIT_ACCESS
    Dim Win32Error As Win32Exception
    Dim ret As Integer

    ' merge this Explict Access with the existing DACL
    ret = SetEntriesInAcl(1, ea, pOldDACL, pNewDACL)
    If ret <> 0 Then
        Win32Error = New Win32Exception(ret)
        Throw New Exception(Win32Error.Message)
    End If

    ' write the new Security Descriptor/DACL back
    ret = SetNamedSecurityInfo(strPath, SE_FILE_OBJECT, DACL_SECURITY_INFORMATION, Nothing, Nothing, pNewDACL, Nothing)
    If ret <> 0 Then
        Win32Error = New Win32Exception(ret)
        Throw New Exception(Win32Error.Message)
    End If

Alternative Managed API:

Do you know one? Please contribute it!