Iconify an external program launched with g_spawn_async_with_pipes

[Giovanni Giunco <giovanni giunco gmail com>]

Hello,

 from a gtk+ application I execute an external program in Windows 7 (64
bit) with administrator privileges, and I use a callback function when it
exits to elaborate the result. So far, it works.
The problem is that I would like to hide or, at least, to minimize
(iconify) the external program to not bore the user.
I guess that I have to manage the GPid value returned
by g_spawn_async_with_pipes,  but how? I didn't find any suitable function
in gtk.

Knowing that GPid is an handle in windows, I used the winapi
functions CloseWindow, ShowWindow, MoveWindow, SetWindowPos. They are
simply and silently ignored during the execution.
Just to check the returned pid, I used TerminateProcess( (HWND)pid , 0) and
 the external application correctly terminated: i.e. pid is correct. On the
other side DestroyWindow is ignored.

Do you have any suggestion?

Below you can find a simplified version of my code.

     #include <windows.h>
     #include <gtk/gtk.h>

    // ... snip ... //

     gchar *argv[3];
     GPid   pid;

    argv[0]= "external_program.exe";
    argv[1]= "external_parameter_file.ini";
    argv[2]= NULL;//

    g_spawn_async_with_pipes  (
                      NULL,       //gchar *working_directory,
                      argv,       //gchar **argv,
                      NULL,       //gchar **envp,
                      G_SPAWN_DO_NOT_REAP_CHILD | G_SPAWN_SEARCH_PATH,
     //GSpawnFlags flags,
                      NULL,       //GSpawnChildSetupFunc child_setup,
                      NULL,       //gpointer user_data,
                      &pid,       //GPid *child_pid,
                      NULL,       //gint *standard_input,
                      NULL,       //gint *standard_output,
                      NULL,       //gint *standard_error,
                      error);     //GError **error);

        /* Add watch function to elaborate the result
of external_program.exe. It will clean any remnants of process. */
        g_child_watch_add( pid, (GChildWatchFunc)child_watch_cb, data );
        CloseWindow((HWND)pid); // ignored during execution!!!

        // I tried also the following variants that are "ignored":
        // ShowWindow((HWND)pid, SW_FORCEMINIMIZE); // Tested also other
options: SW_HIDE, SW_MINIMIZE, SW_SHOWMINIMIZED, SW_SHOWMINNOACTIVE
        // MoveWindow((HWND)pid, 10, 10, 10, 10, TRUE);
        // SetWindowPos( (HWND)pid, 0, 0, 0, 0, 0, SWP_HIDEWINDOW |
SWP_NOMOVE | SWP_NOZORDER | SWP_NOSIZE );

        // This works and terminates the external application, but this is
not obviously my goal
        // TerminateProcess( (HWND)pid , 0);

    // ... snip ... //

/Giovanni