Friend Declare Function EnumWindows Lib "user32.dll" (ByVal lpEnumFunc As EnumWindowsProc, ByVal lParam As Int32) As Int32

Example:

''' <summary>Gets all the top-level windows</summary>
        ''' <returns>List of all top-level windows</returns>
        ''' <exception cref="API.Win32APIException">An error occured</exception>
        Public Shared ReadOnly Property TopLevelWindows() As IReadOnlyList(Of Win32Window)
            Get
                Dim List As New List(Of Win32Window)
                If API.EnumWindows(New API.EnumWindowsProc(Function(hWnd As Integer, lParam As Integer) AddToList(List, New Win32Window(hWnd))), 0) Then
                    Return New ReadOnlyListAdapter(Of Win32Window)(List)
                Else
                    Dim ex As New API.Win32APIException
                    If ex.NativeErrorCode <> 0 Then
                        Throw ex
                    Else
                        Return New ReadOnlyListAdapter(Of Win32Window)(List)
                    End If
                End If
            End Get
        End Property
	''' <summary>Adds <paramref name="item"/> to <paramref name="List"/> and returns true</summary>
        ''' <param name="List"><see cref="List(Of T)"/> to add item to</param>
        ''' <param name="item">Item to be added</param>
        ''' <typeparam name="T">Type of <paramref name="item"/></typeparam>
        ''' <returns>True</returns>
        Private Shared Function AddToList(Of T)(ByVal List As List(Of T), ByVal item As T) As Boolean
            List.Add(item)
            Return True
        End Function

I have a program that is looking for another program to communicate with. It works if you run it from the desktop (explorer), but if I schedule it as a schedule task, enumwindows() only calls the callback function once, then no more.

In the below code, g_hProc is getting set correctly, regardless of the code running as a normal app or a scheduled task. However, g_hWnd never gets set, because enumWindowProc() only gets called once. It properly enumerates if run as a regular app???? (Note: g_appTitle is the name of the window we're looking for, and this object is basically a version of CString.)

If anybody has a fix, please email me at bret @ levycodev dot com.

Thanks,

Bret

BOOL CALLBACK enumWindowsProc (HWND hwnd, LPARAM lParam) {

DWORD procid;

GetWindowThreadProcessId (hwnd, &procid);

if ((HANDLE)procid == g_hProc) {

staticchar module[1024];

module[0] = 0;

if (g_softPhoneTitle.Size() > 0) {

int rc = GetWindowText (hwnd, module, 1023);

module[rc] = 0;

}

if (IsWindow(hwnd) && ((g_appTitle.Size() == 0) || (g_appTitle.EqualsNoCase(module)))) {

g_hWnd = hwnd;

return (false);

}

}

return (true);

}

int

g_hWnd = NULL;

EnumWindows (enumWindowsProc, 0);

return (0);

}

<DllImport("user32.dll", CharSet:=CharSet.Auto, SetLastError:=True)> _
Public Shared Function EnumWindows(ByVal callback As EnumThreadWindowsCallback, ByVal extraData As IntPtr) As Boolean
End Function

[DllImport("user32.dll", CharSet=CharSet.Auto, SetLastError=true)]
public static extern bool EnumWindows(EnumThreadWindowsCallback callback, IntPtr extraData);