private unsafe bool FindSelectedRadioButtonChild(IntPtr hwnd, void *lParam) { // Only be concerned with [....] child controls. if (!WindowsFormsHelper.IsWindowsFormsControl(hwnd)) { return(true); } Accessible acc = null; if (Accessible.AccessibleObjectFromWindow(hwnd, NativeMethods.OBJID_CLIENT, ref acc) == NativeMethods.S_OK && acc != null && acc.Role == AccessibleRole.RadioButton && acc.HasState(AccessibleState.Checked)) { *(IntPtr *)lParam = hwnd; return(false); } return(true); }