The AccessibleObjectFromWindow function retrieves the address of the specified interface to the object associated with the given window.

C# Signature:

    [DllImport("oleacc.dll")]
    internal static extern int AccessibleObjectFromWindow(
    public static extern int AccessibleObjectFromWindow(
         IntPtr hwnd,
         uint id,
         ref Guid iid,
         [In, Out, MarshalAs(UnmanagedType.IUnknown)] ref object ppvObject);    

VB .Net Signature:

    Private Declare Function AccessibleObjectFromWindow Lib "oleacc" (ByVal Hwnd As Int32, _
    ByVal dwId As Int32, _
    ByRef riid As Guid, _
    <MarshalAs(UnmanagedType.IUnknown)> ByRef ppvObject As Object) As Int32

User-Defined Types:

None.

Notes:

None.

Tips & Tricks:

Please add some!

Sample Code:

Visual Basic

    Private Declare Function AccessibleObjectFromWindow Lib "oleacc" (ByVal Hwnd As Int32, _
    ByVal dwId As Int32, _
    ByRef riid As Guid, _
    <MarshalAs(UnmanagedType.IUnknown)> ByRef ppvObject As Object) As Int32
    Declare Function GetForegroundWindow Lib "user32" () As Int32

    Private Sub Form2_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles MyBase.Load
    Dim varChild As Accessibility.IAccessible
    Dim hWnd As Int32 = GetForegroundWindow()
    Dim ID As Int32 = 0
    Dim IID_IAcce As Guid = New Guid("618736E0-3C3D-11CF-810C-00AA00389B71")
    Dim aaVal As Int32 = AccessibleObjectFromWindow(hWnd, ID, IID_IAcce, varChild)
    End Sub

C#

    internal enum OBJID : uint
    {
        WINDOW = 0x00000000,
        SYSMENU = 0xFFFFFFFF,
        TITLEBAR = 0xFFFFFFFE,
        MENU = 0xFFFFFFFD,
        CLIENT = 0xFFFFFFFC,
        VSCROLL = 0xFFFFFFFB,
        HSCROLL = 0xFFFFFFFA,
        SIZEGRIP = 0xFFFFFFF9,
        CARET = 0xFFFFFFF8,
        CURSOR = 0xFFFFFFF7,
        ALERT = 0xFFFFFFF6,
        SOUND = 0xFFFFFFF5,
    }

    Guid guid = new Guid("{618736E0-3C3D-11CF-810C-00AA00389B71}");
    Guid guid = new Guid("{E6DF9A83-13F5-41a3-9BBC-D75592284FF9}");
    object obj = null;
    int retVal = AccessibleObjectFromWindow(hwnd, (uint)OBJID.WINDOW, ref guid, ref obj);
    accessible = (IAccessible) obj;

Alternative Managed API:

The ManagedWindowsApi project (http://mwinapi.sourceforge.net) provides a SystemAccessibleObject class to access accessible objects, that can be instantiated from a window.

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).